As filed with the Securities and Exchange Commission on March 2, 1999
 
                                                             File No. 333-
 
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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
 
                               ----------------
                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
 
                               ----------------
                                 LHS GROUP INC.
             (Exact name of registrant as specified in its charter)
 


                 Delaware                                 58-2224883
                                         
       (State or other jurisdiction         (I.R.S. Employer Identification Number)
     of incorporation or organization)

 
                       Six Concourse Parkway, Suite 2700
                             Atlanta, Georgia 30328
                                 (770) 280-3000
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
 
                               Dr. Wolf J. Gaede
                       Six Concourse Parkway, Suite 2700
                             Atlanta, Georgia 30328
                                 (770) 280-3000
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
 
                                   Copies to:
       M. Hill Jeffries, Esq.                        Marlene Alva, Esq.
         Alston & Bird LLP                         Davis Polk & Wardwell
        One Atlantic Center                         450 Lexington Avenue
     1201 West Peachtree Street                   New York, New York 10017
    Atlanta, Georgia 30309-3424                     (212) 450-4000 (212)
        (404) 881-7000 (404)                           450-5760 (fax)
           881-4777 (fax)
 
   Approximate date of commencement of proposed sale to the public: As soon as
practicable after this Registration Statement becomes effective.
   If the only securities being registered on this form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. [_]
   If any of the securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or
interest reinvestment plans, check the following box. [_]
   If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following
box and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. [_]
   If this form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [_]
   If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [_]
                               ----------------
 
                        CALCULATION OF REGISTRATION FEE
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                                                            Proposed
                                             Proposed       Maximum
                              Amount         Maximum       Aggregate      Amount of
 Title of Shares to be        to be       Offering Price    Offering     Registration
       Registered         Registered(1)    per Share(2)     Price(2)        Fee(2)
- -------------------------------------------------------------------------------------
                                                            
Common stock, $.01 par      3,735,000
 value per share........      shares          $43.69      $163,182,150     $45,365

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(1) Includes 400,000 shares which the placement agents have the option to
purchase from one of the selling stockholders solely to cover over-allotments,
if any. See "Plan of Distribution."
(2) The shares of common stock being registered hereby are being offered by the
selling stockholders in an international offering outside the United States.
Offers and sales will be made in Euros. Pursuant to Rule 457(c), the proposed
maximum offering price per share and registration fee are based on the average
of the high and low sale prices of the registrant's common stock on February
25, 1999 as reported on the Nasdaq National Market.
                               ----------------
 
   The registrant hereby amends this Registration Statement on such date or
dates as may be necessary to delay its effective date until the registrant
shall file a further amendment which specifically states that this Registration
Statement shall thereafter become effective in accordance with Section 8(a) of
the Securities Act of 1933 or until the Registration Statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a),
may determine.
 
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                   SUBJECT TO COMPLETION, DATED MARCH 2, 1999
 
                                 LHS GROUP INC.
                                     [LOGO]
 
                                3,335,000 Shares
 
                                  Common Stock
 
  This is a public offering of 3,335,000 shares of common stock of LHS Group
Inc. Selling stockholders identified in this prospectus are offering all of the
shares to be sold in the offering. All of the shares are being offered in an
international offering outside the United States. LHS will not receive any of
the proceeds of the offering.
 
  Our common stock is listed on the Nasdaq National Market under the symbol
"LHSG" and on the Frankfurt Neuer Markt Exchange under the symbol "LHI." On
March 1, 1999, the last reported sale price of the common stock on the Nasdaq
National Market was $43.88 per share. On February 25, 1999, the last reported
sale price of the common stock on the Frankfurt Neuer Markt was (euro)40.00 per
share.
 
  The public offering price is (euro)     per share. This is equivalent to a 
price of $ per share at an exchange rate of (euro) per $1.00 and a price of per
share at an exchange rate of (euro) per .
 


                                                                Per Share Total
                                                                --------- -----
                                                                    
Public Offering Price.......................................... (euro)  (euro)
Agents' Fee.................................................... (euro)  (euro)
Proceeds to Selling Stockholders............................... (euro)  (euro)

 
  The selling stockholders and we have retained the investment banking firms
named below as placement agents to offer and sell the shares for the selling
stockholders on a best efforts basis. One of the selling stockholders has
granted the placement agents an option to purchase up to 400,000 additional
shares of common stock to cover over-allotments.
 
  Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved these securities or passed upon the
accuracy or adequacy of this prospectus. Any representation to the contrary is
a criminal offense.
                            Deutsche Bank Securities
HypoVereinsbank AG                                                     SG Cowen
 
                   The date of this prospectus is     , 1999.
 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+The information in this prospectus is not complete and may be changed. We may +
+not sell these securities until the registration statement filed with the     +
+Securities and Exchange Commission is effective. This prospectus is not an    +
+offer to sell these securities, and it is not soliciting an offer to buy      +
+these securities in any state where the offer or sale is not permitted.       +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


 
                                      LHS
 
   LHS provides client/server-based billing and customer care solutions to
providers of telecommunications services in the Americas, Europe and Asia. Our
products enable these carriers to compete more effectively in a rapidly growing
wireless and wireline telecommunications market. Our Business Support and
Control System software is a scaleable, modular billing and customer care
solution that can be implemented quickly and can support innovative marketing
and pricing of telecommunications services. We have licensed BSCS to
approximately 134 carriers in over 70 countries, and BSCS currently supports
approximately 24.8 million subscribers.
 
   Our headquarters are located at Six Concourse Parkway, Suite 2700, Atlanta,
Georgia 30328. Our telephone number at that location is (770) 280-3000.
 
                              RECENT DEVELOPMENTS
 
   On February 22, 1999, we announced revenue for the quarter and year ended
December 31, 1998 of $48.3 million and $163.2 million. Our earnings and diluted
earnings per share for the same periods were $7.9 million and $0.15 and $17.3
million and $0.32. These financial results have not been audited by our
independent auditors yet.
 
   Also, on February 22, 1999, we announced the launch of our object-oriented
next generation customer care and billing software "Targys--the millennium
series" for the global telecommunications industry. Targys is based on a multi-
tiered component-based architecture employing Java as its implementation
language. It allows plug-and-play interoperability with other software that
supports CORBA 2, an industry standard introduced by the Object Management
Group. The first application of the Targys series is now in use at Swisscom AG
Mobile, Bern, Switzerland.
 
                                  RISK FACTORS
 
   For information regarding certain considerations that a prospective
purchaser of the common stock should consider, see "Risk Factors" contained in
our Current Report on Form 8-K dated March 1, 1999 on file with the SEC. The
Form 8-K is incorporated in this prospectus by reference.
 
                                USE OF PROCEEDS
 
   The selling stockholders are selling all of the shares of common stock being
offered. LHS will not receive any of the proceeds from the sales by the selling
stockholders.
 
                                       2

 
                   PRICE RANGE OF COMMON STOCK AND DIVIDENDS
 
   The common stock began trading on the Nasdaq National Market on May 16, 1997
under the symbol "LHSG." The common stock began trading on the Frankfurt Neuer
Markt Exchange on May 21, 1997 under the symbol "LHI." The high and low
quarterly sales prices of the common stock on the Nasdaq National Market and
the Frankfurt Neuer Markt Exchange since the commencement of trading, as
reported by Nasdaq and the Frankfurt Neuer Markt Exchange, are as follows:
 


                                                   Nasdaq
                                                  National     Frankfurt Neuer
                                                  Market(1)   Markt Exchange(2)
                                                ------------- -----------------
                                                 High   Low     High     Low
                                                ------ ------ -------- --------
                                                           
   1999
   First Quarter(3)............................ $59.13 $43.00 (E)50.00 (E)39.20
 
   1998
   First Quarter............................... $50.38 $25.50 DM 87.25 DM 48.05
   Second Quarter..............................  73.75  44.50   130.00    84.00
   Third Quarter...............................  76.50  43.94   129.90    76.25
   Fourth Quarter..............................  57.38  36.75    90.90    61.00
 
   1997
   First Quarter...............................     NA     NA       NA       NA
   Second Quarter.............................. $22.25 $ 9.38 DM 37.15 DM 19.05
   Third Quarter...............................  30.75  21.56    56.75    37.95
   Fourth Quarter..............................  37.88  19.38    56.05    35.50

- --------
(1) Prices of shares of common stock are in U.S. Dollars.
(2) Prices of shares of common stock are in German Deutsche Mark for periods
    prior to January 1, 1999 and in Euros for subsequent periods. On January 1,
    1999, the exchange rate of the German Deutsche Mark was fixed against the
    Euro at 1.9559 Deutsche Mark per Euro.
(3) Through March 1, 1999.
 
   We have not paid cash dividends on our common stock since 1994. We currently
intend to retain any future earnings to fund the continued development and
growth of our business. We therefore do not anticipate paying cash dividends in
the foreseeable future.
 
                                       3


 
                              SELLING STOCKHOLDERS
 
   The following table provides information as of February 26, 1999 about the
ownership of our common stock by each of the selling stockholders and the
number of shares being offered for sale by them:
 


                                 Shares                              Shares
                           Beneficially Owned     Number of    Beneficially Owned
          Name             Before Offering(1)    Shares Being  After Offering(1)
          ----             --------------------- ------------  ------------------
                             Number      Percent   Offered(2)    Number   Percent
                           ----------    ------- ------------  ---------- -------
                                                           
General Atlantic Part-
 ners, LLC,
 William E. Ford and
 William O. Grabe........   8,374,578(3)  15.9%   2,500,000     5,874,578  11.1%
 
Hartmut Lademacher
Chairman of the Board and
 Chief Executive Offi-
 cer.....................  19,506,333(4)  36.1%     500,000    16,506,333  30.6%
 
Dr. Hansjorg Beha
 Executive Vice President
 of Technology...........      67,500(5)     *       60,000         7,500     *
 
Ulf Bohla
 Director................      19,375(6)     *       17,000         2,375     *
 
Jerry W. Braxton
 Executive Vice Presi-
 dent,
 Chief Financial Officer
 and Treasurer ..........     114,113(7)     *       80,000        34,113     *
 
Erik Froberg
 Special Advisor to the
 Chairman of Board ......     162,500(8)     *      150,000        12,500     *
 
Jon Limbird
 Executive Vice President
 of
 Corporate Development...      31,875(9)     *       28,000         3,875     *

- --------
 
*Less than one percent.
 
(1) The number of shares of common stock beneficially owned by a person or
    group includes shares issuable on or before April 30, 1999 pursuant to
    convertible securities, warrants and options. Such shares are considered to
    be outstanding for the purpose of computing the percentage of the class
    beneficially owned by such person or group but are not considered to be
    outstanding for the purpose of computing the percentage of the class owned
    by any other person or group.
(2) Excludes 400,000 shares as to which General Atlantic Partners, LLC, has
    granted the placement agents an over-allotment option. See "Plan of
    Distribution."
(3) Includes (a) 4,941,006 shares of common stock held by General Atlantic
    Partners 23, L.P. ("GAP 23"), (b) 2,040,931 shares of common stock held by
    General Atlantic Partners 31, L.P. ("GAP 31"), (c) 1,179,406 shares of
    common stock owned by GAP Coinvestment Partners, L.P. ("GAP Coinvestment"),
    (d) 10,000 shares of common stock and options to purchase an additional
    100,000 shares of common stock held by Mr. Ford, and (e) 91,235 shares of
    common stock held by Mr. Grabe and 6,000 shares of common stock held by
    each of Mr. Grabe's two minor children. We refer to GAP 23, GAP 31 and GAP
    Coinvestment as the "general atlantic stockholders." The general partner of
    GAP 31 and GAP 23 is General Atlantic Partners, LLC ("GAP LLC"). The
    managing members of GAP LLC are Steven A. Denning, David C. Hodgson, J.
    Michael Cline, William O. Grabe, Peter L. Bloom, William E. Ford and
    Franchon M. Smithson. The managing members of GAP LLC are the general
    partners of GAP Coinvestment. Messrs. Ford and Grabe, directors of the
    Company, are managing members of GAP LLC and general partners of GAP
    Coinvestment. Mr. Ford and Mr. Grabe disclaim beneficial ownership of
    shares owned by the general atlantic stockholders, except to the extent of
    their respective pecuniary interests therein. The general atlantic
    stockholders disclaim beneficial ownership of the shares of
 
                                       4


 
    common stock and options to purchase common stock held by Mr. Ford and the
    shares of common stock held by Mr. Grabe and his minor children. The
    address for the general atlantic stockholders, GAP LLC, Mr. Ford and Mr.
    Grabe is c/o General Atlantic Service Corporation, 3 Pickwick Plaza,
    Greenwich, CT 06830.
(4) Includes (a) options to purchase 68,751 shares of common stock and (b)
    14,056,332 shares, the beneficial holders of which have granted to Mr.
    Lademacher the right to vote such shares in his discretion. The voting
    rights expire on December 31, 1999. Mr. Lademacher's address is LHS Group
    Inc., Six Concourse Parkway, Suite 2700, Atlanta, Georgia 30328.
(5) Represents options to purchase shares of common stock.
(6) Represents options to purchase shares of common stock.
(7) Includes options to purchase 110,113 shares of common stock.
(8) Represents options to purchase shares of common stock.
(9) Represents options to purchase shares of common stock.
 
   The nature of any position, office or other material relationship which the
selling stockholders have had within the past three years with LHS or any of
its affiliates is set forth below.
 
   In connection with a reorganization of LHS in December 1995, GAP 23 and GAP
Coinvestment purchased a total of 225,000 shares of Series A convertible
preferred stock from LHS. At the same time, Messrs. Ford and Grabe, as the
designees of GAP LLC, were elected as directors of LHS. In May 1997, the
225,000 shares of Series A convertible preferred stock were converted into a
total of 4,500,000 shares of common stock.
 
   In July 1996, LHS repurchased 1,861,560 shares of common stock from one of
its stockholders at a price of $10,000,000. Simultaneously, LHS sold 1,601,920
shares of common stock to GAP 31 at a price of $8,605,514 and sold 259,640
shares of common stock to GAP Coinvestment at a price of $1,394,786.
 
   Hartmut Lademacher is one of the founders of LHS and has served as Chairman
of the Board and Chief Executive Officer since our inception in October 1990.
On December 12 and 13, 1996, Mr. Lademacher sold 50,000 shares of common stock
to GAP Coinvestment at a price of $837,500.
 
   In connection with the reorganization in December 1995, LHS, the general
atlantic stockholders and the other stockholders of LHS, including Hartmut
Lademacher (the "major stockholders"), entered into a stockholders agreement
and a registration rights agreement. The stockholders agreement terminated
upon the completion of our initial public offering in May 1997. The
registration rights agreement entitles each of the general atlantic
stockholders as a group and the major stockholders as a group to require LHS
on up to two occasions for each group to register all or part of their shares
under the Securities Act of 1933. The registration rights agreement also
allows the general atlantic stockholders and the major stockholders to
participate in any offering of common stock by LHS. The registration rights
agreement remains in effect, and neither the general atlantic stockholders nor
the major stockholders have exercised any of their demand registration rights.
 
   A subsidiary of LHS leases office space in Frankfurt, Germany from a
corporation of which Hartmut Lademacher owns 25%. During the years ended
December 31, 1996, 1997 and 1998, LHS made lease payments totaling $370,000,
$329,000 and $316,000 to this corporation.
 
   In connection with an LHS project in Dusseldorf, Germany, a subsidiary of
LHS leased housing space for its employees in 1996 and 1997. This space is
owned by a partnership in which Hartmut Lademacher holds a one-third interest.
During the years ended December 31, 1996, 1997 and 1998, we made lease
payments of approximately $67,000, $58,000 and $66,000 to the partnership.
 
   Dr. Hansjorg Beha has been our Executive Vice President of Technology since
December 1997. Jerry W. Braxton has served as our Executive Vice President,
Chief Financial Officer and Treasurer since August 1996 and as a director
since September 1996. Erik Froberg has been the Special Advisor to the
Chairman of the Board since February 1999. From August 1996 to February 1999,
he served as Executive Vice President of LHS and President and Chief Executive
Officer of LHS Holding Germany GmbH. Jon Limbird has been our
 
                                       5


 
Executive Vice President of Corporate Development since January 1, 1999. From
April 1996 to January 1, 1999, Mr. Limbird held the positions of Senior Vice
President of Product Development, Vice President of Research and Development,
and Vice President of Operations.
 
                    MATERIAL U.S. FEDERAL TAX CONSIDERATIONS
                          FOR HOLDERS OF COMMON STOCK
 
   The following are U.S. federal income and estate tax consequences of the
ownership and disposition of common stock by a beneficial holder. For purposes
of this discussion, a U.S. holder is a holder that for United States federal
income tax purposes is:
 
  .  a citizen or individual resident of the United States;
 
  .  a corporation or partnership created or organized in or under the laws of
     the United States or of any political subdivision thereof;
 
  .  an estate the income of which is subject to U.S. federal income taxation
     regardless of its source; or
 
  .  a trust if both (A) a U.S. court is able to exercise primary supervision
     over the administration of the trust and (B) one or more U.S. persons have
     the authority to control all substantial decisions of the trust.
 
A non-U.S. holder is any person or entity that is not a U.S. holder.
 
   This discussion is based on the U.S. Internal Revenue Code of 1986 and
current administrative interpretations. These authorities may change possibly
with a retroactive effect. This discussion does not address all aspects of U.S.
federal income and estate taxation that may be relevant to holders in light of
their particular circumstances. This discussion does not address tax
consequences applicable to persons with special tax status such as financial
institutions, insurance companies, tax-exempt organizations, securities dealers
or pass-through entities. It also does not address any tax consequences to
holders arising under the laws of any state, local or foreign jurisdiction. You
should consult your tax adviser with respect to the particular tax consequences
to you of owning and disposing of common stock, including the consequences
under the laws of any state, local or foreign jurisdiction.
 
Tax Consequences to LHS
 
   LHS will not have any tax consequences as a result of the sale of the common
stock by the selling stockholders.
 
Dividends
 
 U.S. Holders
 
   A distribution by LHS on the common stock generally will be a dividend to
the extent the distribution is paid from the current or accumulated earnings
and profits of LHS as determined under U.S. federal income tax principles. If
you are a U.S. holder, such dividends will be includable in your income for tax
purposes. A distribution in excess of our earnings and profits generally will
first be treated as a nontaxable return of capital to the extent of your basis
in the common stock which will reduce your basis, and then as a gain from the
sale or exchange of a capital asset.
 
 Non-U.S. Holders
 
   Subject to the discussion below, dividends paid to you, if you are a non-
U.S. holder of common stock, will be subject to withholding of United States
federal income tax at a 30% rate, or a lower rate as may be provided by an
income tax treaty between the United States and a foreign country if you are
treated as a resident of such foreign country within the meaning of the
applicable treaty, unless the dividends are effectively connected with the
conduct of your trade or business within the United States and you provide the
payor with proper documentation.
 
   Dividends that are effectively connected with the conduct of your trade or
business within the United States, in some cases, will be subject to United
States federal income tax on a net income basis, after allowance for applicable
deductions, at applicable graduated individual or corporate rates. Any such
effectively connected
 
                                       6

 
dividends received by a foreign corporation may be subject to an additional
"branch profits tax" at a 30% rate or such lower rate as may be specified by an
applicable income tax treaty.
 
   Withholding may be reduced if a tax treaty applies. To obtain a reduced rate
of withholding under a treaty, a non-U.S., holder will be required to provide
appropriate certification as to entitlement to treaty benefits. Please see your
tax adviser to determine whether you are entitled to treaty benefits.
 
   Under regulations recently adopted and effective on January 1, 1999,
dividends paid after December 31, 1998, will be subject to United States
withholding tax at a 31% rate under the backup withholding rules described
below, rather than at a 30% rate or a reduced rate under an income tax treaty,
as described above, unless you comply with appropriate U.S. Internal Revenue
Service certification procedures or, in the case of payments made outside the
United States with respect to an offshore account, certain IRS documentary
evidence procedures. In addition, you must comply with certain IRS
certification and disclosure requirements in order to be exempt from
withholding under the effectively connected income exemption. The new
regulations also provide special rules for dividend payments made to:
 
  .  foreign intermediaries;
 
  .  U.S. or foreign wholly owned entities that are disregarded for U.S.
     federal income tax purposes; and
 
  .  entities that are treated as fiscally transparent in the United States,
     the applicable income tax treaty jurisdiction or both.
 
You should consult with your tax adviser concerning the effect of the adoption
of these new regulations on an investment in the common stock.
 
Gain on Disposition of Common Stock
 
 U.S. Holders
 
   If you are a U.S. holder, you will recognize a gain or loss on the taxable
disposition of the common stock in an amount equal to the difference between
your adjusted tax basis in the common stock and the amount realized on its
disposition. Your adjusted tax basis in the common stock will generally be
equal to the cost of the acquired shares reduced, not below zero, by the amount
of any distribution that is treated as a tax-free return of basis. The gain or
loss generally will be capital gain or loss, long-term or short-term, depending
on whether or not you held the common stock for more than one year. The
provisions of the IRS Reform Act of 1998 reduced the maximum capital gains rate
for individuals to 20% for capital assets held for more than 12 months before
disposition; the rate applicable to gain realized on the disposition of common
stock by you will depend upon the holding period of such common stock, your
other taxable income and other factors.
 
 Non-U.S. Holders
 
   If you are a non-U.S. holder, you generally will not be subject to United
States federal income tax with respect to gain recognized on a sale or other
disposition of common stock unless:
 
  .  the gain is effectively connected with a trade or business conducted by
     you within the United States;
 
  .  if you are an individual and hold the common stock as a capital asset, you
     are present in the United States for 183 or more days in the taxable year
     of the sale or other disposition and other conditions are met;
 
  .  you are subject to tax pursuant to specific provisions of the Internal
     Revenue Code applicable to United States expatriates; or
 
  .  LHS is or has been a U.S. real property holding corporation for United
     States federal income tax purposes at any time within the shorter of the
     five-year period preceding such disposition or the period you held the
     common stock.
 
   A corporation is a U.S. real property holding corporation if the fair market
value of the United States real property interests held by the corporation is
50% or more of the aggregate fair market value of specific assets of the
corporation. LHS is not, and does not anticipate becoming, a U.S. real property
holding corporation.
 
                                       7

 
   If you are a non-U.S. holder who is an individual and you fall under the
first bullet point above, you generally will be taxed on the net gain derived
from a sale of common stock under regular graduated United States federal
income tax rates. If you fall under the second bullet point above, you
generally will be subject to a flat 30% tax on the gain derived from a sale,
which may be offset by certain United States capital losses, notwithstanding
the fact that you are not considered a resident alien of the United States.
Individual non-U.S. holders who have spent or expect to spend more than a short
period of time in the United States in the taxable year in which they
contemplate a sale of common stock are urged to consult their tax advisers
prior to the sale of common stock as to the U.S. tax consequences of such sale.
 
   If you are a non-U.S. holder that is a foreign corporation and you fall
under the first bullet point above, you generally will be taxed on your net
gain under regular graduated United States federal income tax rates and will be
subject to the branch profits tax equal to 30% of your "effectively connected
earnings and profits," within the meaning of the Code, for the taxable year, as
adjusted for certain items. The United States federal income tax on gain
recognized by non-U.S. holders may be reduced or eliminated under an applicable
treaty. Please consult your tax adviser to determine whether you are entitled
to treaty benefits.
 
Information Reporting Requirements and Backup Withholding
 
   Generally, LHS must report to the IRS the amount of dividends paid, the name
and address of the recipient and the amount of any tax withheld. A similar
report is sent to the holder. Pursuant to tax treaties or other agreements, the
IRS may also make its reports available to tax authorities in the recipient's
country of residence.
 
 U.S. Holders
 
   Dividends paid to you, as a U.S. holder, may be subject to backup
withholding at the rate of 31% unless you:
 
  .  are a corporation or come within other exempt categories and, when
     required, demonstrate this fact, or
 
  .  provide a taxpayer identification number, certify as to no loss of
     exemption from backup withholding, and otherwise comply with the
     applicable requirements of the backup withholding rules.
 
 Non-U.S. Holders
 
   Under United States Treasury regulations, LHS must report annually to the
IRS and to each non-U.S. holder the amount of dividends paid to a non-U.S.
holder and the tax withheld with respect to these dividends. These information
reporting requirements apply even if withholding was not required because the
dividends were effectively connected with your trade or business in the United
States or withholding was reduced or eliminated by an applicable income tax
treaty. Copies of the information returns reporting such dividends and
withholding may also be made available to the tax authorities in the country in
which you are a resident under the provisions of an applicable income tax
treaty or agreement.
 
   United States backup withholding is a withholding tax imposed at the rate of
31% on payments to persons that fail to furnish required information under the
United States information reporting requirements. Backup withholding generally
will not apply to dividends paid to you that are subject to the 30% withholding
discussed above or that are not so subject because a tax treaty applies that
reduces or eliminates such 30% withholding. However, under newly issued
Treasury regulations, in the case of dividends paid after December 31, 1998,
you generally will be subject to backup withholding at a 31% rate, unless you
comply with IRS certification procedures or, in the case of payments made
outside the United States with respect to an offshore account, IRS documentary
evidence procedures.
 
   Backup withholding and information reporting generally will apply to
dividends paid to addresses inside the United States on shares of common stock
to beneficial owners that are not "exempt recipients" and that fail to provide
certain identifying information in the manner required.
 
                                       8

 
   Under current United States federal income tax law, information reporting
and backup withholding imposed at a rate of 31% will apply to the proceeds of a
disposition of common stock paid to or through a U.S. office of a broker unless
the disposing holder certifies as to its non-U.S. status or otherwise
establishes an exemption. In general, backup withholding and information
reporting will not apply to a payment of the gross proceeds of a sale of common
stock effected at a foreign office of a broker. After December 31, 1998, under
the newly issued Treasury regulations referred to above, information reporting
and backup withholding may apply to payments of the gross proceeds from the
sale or redemption of common stock effected through foreign offices of brokers
having any of a broader class of connections with the United States unless
certain IRS certification requirements are complied with. You should consult
with your tax adviser regarding these Treasury regulations and, in particular,
with respect to whether the use of a particular broker would subject you to
these rules.
 
   Payment by a United States office of a broker of the proceeds of a sale of
common stock is subject to both backup withholding and information reporting
unless the beneficial owner certifies under penalties of perjury that it is a
non-U.S. holder or otherwise establishes an exemption. Backup withholding is
not an additional tax. Any amounts withheld under the backup withholding rules
will be allowed as a refund or a credit against such holder's United States
federal income tax liability provided the required information is furnished to
the IRS.
 
Federal Estate Tax Applicable to Non-U.S. Holders
 
   An individual non-U.S. holder who at the time of death is treated as the
owner of, or has made certain lifetime transfers of, an interest in the common
stock will be required to include the value thereof in his gross estate for
U.S. federal estate tax purposes and may be subject to U.S. federal estate tax
unless an applicable estate tax treaty provides otherwise.
 
                              PLAN OF DISTRIBUTION
 
   The selling stockholders and LHS have entered into a placement agreement
dated March    , 1999 with the placement agents: Deutsche Bank Securities,
Bayerische Hypo-und Vereinsbank AG and SG Cowen International L.P. Pursuant to
the placement agreement, the placement agents have agreed to use their best
efforts in acting as agents for the selling stockholders to place 3,185,000
shares of common stock with third-party purchasers. The placement agents may
also exercise an over-allotment option allowing them to place up to an
additional 400,000 shares. The selling stockholders expect to sell all of the
shares to non-U.S. persons outside of the United States. The selling
stockholders may sell some shares to U.S. persons. Any of the selling
stockholders may withdraw from the placement agreement until March 8, 1999
without penalty.
 
   The selling stockholders are acting as principals for their own accounts.
The placement agents will not underwrite the transaction by purchasing the
shares as principal and then reselling them, although:
 
  .  in their role as agents, they may purchase some of the shares for their
     own account; and
 
  .  they may distribute the shares through block trades in which they attempt
     to sell the shares as agents, but they may position and resell a portion
     of the block as principal to facilitate the transaction.
 
   The selling stockholders have advised LHS that they may sell the shares,
through the placement agents, in one or more:
 
  .  transactions on the Frankfurt Neuer Markt and/or the Nasdaq National
     Market;
 
  .  sales occurring in the public market off such exchanges;
 
  .  negotiated transactions;
 
  .  purchases or writing of options on the shares; or
 
  .  short sales.
 
                                       9

 
   The selling stockholders, through the placement agents, will sell the
shares:
 
    . at prices and on terms then prevailing;
 
    . at prices related to the then-current market price of the shares; or
 
    . at negotiated prices.
 
   LHS will receive no proceeds from the sale of the shares by the selling
stockholders. The selling stockholders will pay all registration expenses in
connection with this offering, as well as all brokerage commissions and other
expenses incurred by the selling stockholders. The selling stockholders and LHS
have agreed to indemnify the placement agents in certain circumstances against
certain liabilities, including liabilities arising under the Securities Act.
 
   The placement agents will receive a flat commission on each share placed for
providing the customary services of placement agents. If the placement agents
succeed in placing any shares at prices above thresholds specified in the
placement agreement, they will receive a bonus payment representing a fixed
percentage of the excess above the threshold price for each such share.
 
   The selling stockholders and the placement agents may be considered
"underwriters" within the meaning of Section 2(11) of the Securities Act. In
such event, any profit on the sale of the shares received by the selling
stockholders and any commissions received by the placement agents may be deemed
to be underwriting discounts and commissions under the Securities Act. The
selling stockholders and the placement agents will deliver a copy of this
prospectus to any U.S. person who purchases any of the shares through them.
 
                                 LEGAL MATTERS
 
   Certain legal matters with regard to the shares of common stock offered will
be passed upon for LHS by Alston & Bird LLP, Atlanta, Georgia.
 
                                    EXPERTS
 
   Ernst & Young LLP, independent auditors, have audited our consolidated
financial statements and schedule included and/or incorporated by reference in
our Annual Report on Form 10-K for the year ended December 31, 1997, as set
forth in their report, which is incorporated in this prospectus by reference.
Our consolidated financial statements are incorporated by reference in reliance
on their authority as experts in accounting and auditing.
 
   Paresky Flitt & Company, independent auditors, have audited the financial
statements of Infocellular, Inc. for the years ended March 31, 1998 and 1997
included in our Current Report on Form 8-K dated July 20, 1998, as set forth in
their report, which is incorporated in this prospectus by reference. The
financial statements of Infocellular, Inc. are incorporated by reference in
reliance on their report, given on their authority as experts in accounting and
auditing.
 
 
                                       10

 
               SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
 
   Some of the statements in this prospectus, including some statements in
other documents that we incorporate by reference, are forward-looking
statements about what may happen in the future. They include statements
regarding our current beliefs, goals and expectations about matters such as
our expected financial position and operating results, our business strategy
and our financing plans. These statements can sometimes be identified by our
use of forward-looking words such as "anticipate," "estimate," "expect,"
"intend," "may," "should," "will" and similar expressions. Our forward-looking
statements are subject to numerous risks, uncertainties and assumptions,
including those discussed in the reports that we file with the Securities and
Exchange Commission. We cannot guarantee that our forward-looking statements
will turn out to be correct or that our beliefs and goals will not change. Our
actual results could be very different from and worse than our expectations as
expressed in our forward-looking statements.
 
                      WHERE YOU CAN FIND MORE INFORMATION
 
   We file annual, quarterly and special reports, proxy statements and other
information with the SEC. Our SEC filings are available to the public over the
Internet at the SEC's web site at http://www.sec.gov. You may also read and
copy any document we file at the SEC's Public Reference Room in Washington,
D.C. Please call the SEC at 1-800-SEC-0330 for further information on the
Public Reference Room.
 
   Our common stock is listed on the Nasdaq National Market, and you may also
read and copy our SEC filings at The Nasdaq Stock Market, 1735 K Street, N.W.,
Washington, D.C. 20006.
 
   The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information that we incorporate by
reference is considered to be part of this prospectus, and information that we
file later with the SEC will automatically update and supersede the
information in this prospectus. We incorporate by reference the documents
listed below and any future filings made with the SEC under Sections 13(a),
13(c), 14, or 15(d) of the Securities Exchange Act of 1934 until the offering
is completed.
 
  (a) Annual Report on Form 10-K for the year ended December 31, 1997;
 
  (b) Quarterly Reports on Form 10-Q for the quarters ended March 31, 1998,
      June 30, 1998 and September 30, 1998, as amended by Quarterly Report
      on Form 10-Q/A filed on January 27, 1999;
 
  (c) Current Report on Form 8-K dated June 29, 1998, as amended by Current
      Report on Form 8-K/A filed on July 20, 1998, and Current Report on
      Form 8-K dated February 26, 1999;
 
  (d) The description of our common stock contained in Form 8-A (Item 1)
      dated April 21, 1997.
 
   You may request a copy of these filings at no cost by writing or
telephoning us at the following address:
 
                 Corporate Secretary
                 LHS Group Inc.
                 Six Concourse Parkway
                 Suite 2700
                 Atlanta, Georgia 30328
                 (770) 280-3000
 
   You should rely only on the information provided or incorporated by
reference in this prospectus. We have authorized no one to provide you with
different information. We are not making an offer of these securities in any
place where the offer is not permitted. You should not assume that the
information in this prospectus is accurate as of any date other than the date
on the front of the document.
 
 
                                      11

 
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   We have not authorized any dealer, salesperson or other person to give any
information or to represent anything not contained in this prospectus. You
must not rely on any unauthorized information or representations. This
prospectus does not offer to sell or buy any shares in any jurisdiction where
it is unlawful to do so. The information contained in this prospectus is
current only as of its date.
 
                               ----------------
 
                               TABLE OF CONTENTS
 


                                                                           Page
                                                                           ----
                                                                        
LHS.......................................................................   2
Recent Developments.......................................................   2
Risk Factors..............................................................   2
Use of Proceeds...........................................................   2
Price Range of Common Stock and Dividends.................................   3
Selling Stockholders......................................................   4
Material U.S. Federal Tax Considerations for Holders of Common Stock......   6
Plan of Distribution......................................................   9
Legal Matters.............................................................  10
Experts...................................................................  10
Special Note Regarding Forward-Looking Statements.........................  11
Where You Can Find More Information.......................................  11

 
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- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
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                                LHS GROUP INC.
 
                               3,335,000 Shares
 
                                 Common Stock
 
                           Deutsche Bank Securities
                              HypoVereinsbank AG
                                   SG Cowen
 
                                  Prospectus
 
                                          , 1999
 
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------

 
                                    PART II
 
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
Item 14. Other Expenses of Issuance and Distribution.
 
   Set forth below are estimates (except for the SEC registration fee and the
NASD filing fee) of the fees and expenses (other than placement agents'
commissions) payable in connection with the offer and sale of the common stock:
 

                                                                    
SEC registration fee.................................................. $ 45,365
NASD filing fee.......................................................   16,095
Legal fees and expenses...............................................   75,000
Accounting fees and expenses..........................................  100,000
Transfer agent fees and expenses......................................    5,000
Printing and engraving expenses.......................................   25,000
Miscellaneous.........................................................   13,540
                                                                       --------
    Total                                                              $280,000
                                                                       ========

- --------
* Payable by the selling stockholders.
 
Item 15. Indemnification of Directors and Officers.
 
     The By-Laws of LHS, a Delaware corporation, provide for indemnification of
directors and officers of LHS to the full extent permitted by Delaware law.
Section 145 of the General Corporation Law of the State of Delaware provides
generally that a corporation may indemnify any person who was or is a party or
is threatened to be made a party to any threatened, pending or completed
action, suit or proceeding, whether civil, criminal, administrative or
investigative, by reason of the fact that he is or was a director, officer,
employee or agent of the corporation, or is or was serving at its request in
such capacity in another corporation or business association, against expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement
actually and reasonably incurred by him in connection with such action, suit or
proceeding if he acted in good faith and in a manner he reasonably believed to
be in or not opposed to the best interests of the corporation, and, with
respect to any criminal action or proceeding, had no reasonable cause to
believe his conduct was unlawful. In addition, pursuant to the authority of
Delaware law, the Certificate of Incorporation of LHS also eliminates the
monetary liability of directors to the fullest extent permitted by Delaware
law.
 
Item 16. Exhibits.
 
   The following exhibits are filed as a part of this Registration Statement:
 


 Exhibit
 Number  Description of Exhibit
 ------- ----------------------
      
  1.1*   Form of Placement Agreement between LHS, the selling stockholders and
         Deutsche Bank Securities Inc., SG Cowen International L.P. and
         Bayerische Hypo-und Vereinsbank AG, as placement agents. (English
         translation of German document)
 
  4.1**  Specimen common stock certificate.
 
  5.1*   Form of opinion of Alston & Bird LLP relating to the legality of the
         shares being offered (including consent).
 
  8.1*   Opinion of Alston & Bird LLP relating to certain tax matters
         (including consent).
 
 23.1*   Consent of Alston & Bird LLP (contained in Exhibits 5.1 and 8.1).
 
 23.2*   Consent of Ernst & Young LLP.
 
 23.3*   Consent of Paresky Flitt & Company.
 
 24.1    Powers of Attorney (contained on signature page).
 
 27.1*** Financial Data Schedule

 
                                      II-1

 
- --------
*  Filed herewith.
** Incorporated by reference to the corresponding numbered exhibit in the
   registrant's Registration Statement on Form S-1, No. 333-22195.
*** Incorporated by referenced to Exhibit 27.1 of the registrant's Annual
    Report on Form 10-K for the year ended December 31, 1997 and Exhibit 27.1
    of the registrant's Quarterly Report on Form 10-Q for the quarter ended
    September 30, 1998.
 
Item 17. Undertakings.
 
   1. The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Securities Exchange Act
of 1934) that is incorporated by reference in the Registration Statement shall
be deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.
 
   2. Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than payment by the registrant
of expenses incurred or paid by a director, officer, or controlling person of
the registrant in the successful defense of any action, suit or proceeding) is
asserted by such director, officer or controlling person of the registrant in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.
 
   3. The undersigned registrant hereby undertakes that:
 
    (a) For purposes of determining any liability under the Securities Act
        of 1933, the information omitted from the form of prospectus filed
        as part of this Registration Statement in reliance upon Rule 430A
        and contained in a form of prospectus filed by the registrant
        pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities
        Act shall be deemed to be part of this Registration Statement as of
        the time it was declared effective.
 
    (b) For the purpose of determining any liability under the Securities
        Act of 1933, each post-effective amendment that contains a form of
        prospectus shall be deemed to be a new Registration Statement
        relating to the securities offered therein, and the offering of
        such securities at that time shall be deemed to be the initial bona
        fide offering thereof.
 
                                      II-2

 
                                   SIGNATURES
 
   Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Atlanta, State of Georgia, on February 24, 1999.
 
                                          LHS GROUP INC.
 
                                              /s/ Hartmut Lademacher
                                          By: _________________________________
                                              Hartmut Lademacher
                                              Chairman of the Board of
                                              Directors and Chief Executive
                                              Officer
 
                               POWER OF ATTORNEY
 
   KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Hartmut Lademacher, Jerry W. Braxton and Dr.
Wolf J. Gaede, and each of them, with the power to act without the other, as
his true and lawful attorneys-in-fact and agents, with full power of
substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities, to sign any and all amendments (including post-
effective amendments) to this Registration Statement, to sign any registration
statement to be filed pursuant to Rule 462(b) under the Securities Act of 1933,
as amended, for the purpose of registering additional shares of Common Stock
for the same offering covered by this Registration Statement, and to file any
of the same, with all exhibits thereto and other documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents, and each of them, full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said attorneys-in-
fact and agents, or any of them, or his or their substitutes, may lawfully do
or cause to be done by virtue hereof.
 
   Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on February 24, 1999.
 


                   Name                                        Title
                   ----                                        -----
                                         
          /s/ Hartmut Lademacher            Chairman of the Board and Chief
___________________________________________  Executive Officer (Principal Executive
            Hartmut Lademacher               Officer)
 
           /s/ Jerry W. Braxton             Executive Vice President, Chief Financial
___________________________________________  Officer, Treasurer and Director
             Jerry W. Braxton                (Principal Financial and Accounting
                                             Officer)
 
           /s/ Dr. Wolf J. Gaede            Executive Vice President, General Counsel
___________________________________________  and Director
             Dr. Wolf J. Gaede
 
               /s/ Ulf Bohla                Director
___________________________________________
                 Ulf Bohla
 
            /s/ William E. Ford             Director
___________________________________________
              William E. Ford
 
           /s/ William O. Grabe             Director
___________________________________________
             William O. Grabe
 
           /s/ George F. Schmitt            Director
___________________________________________
             George F. Schmitt

 
                                      II-3