EXHIBIT 2.4

                               THIRD AMENDMENT TO

                          AGREEMENT AND PLAN OF MERGER

     This THIRD  AMENDMENT TO AGREEMENT  AND PLAN OF MERGER dated as of March 1,
1996 ("Third  Amendment"),  is made by and among Fairchild  Industries,  Inc., a
Delaware corporation ("Fairchild"), RHI Holdings, Inc., a a Delaware corporation
("RHI"), The Fairchild  Corporation,  a Delaware corporation ("TFC"), and Shared
Technologies  Inc., a Delaware  corporation  ("Shared  Technologies"),  amending
certain  provisions  of the Agreement and Plan of Merger dated as of November 9,
1995, as amended by the First Amendment to Agreement and Plan of Merger dated as
of February 2, 1996 (the "First  Amendment"),  as further  amended by the Second
Amendment  to  Agreement  and Plan of Merger  dated as of February 23, 1996 (the
"Second Amendment"), including the exhibits and schedules thereto (the Agreement
and Plan of Merger,  as amended by the First Amendment and the Second Amendment,
are  referred to  collectively  herein as the "Merger  Agreement")  by and among
Fairchild, RHI, TFC and Shared Technologies.  Terms not otherwise defined herein
which  are  defined  in the  Merger  Agreement  shall  have the same  respective
meanings herein as therein.

     WHEREAS,  Fairchild, RHI, TFC and Shared Technologies have agreed to modify
certain terms and conditions of the Merger  Agreement as specifically  set forth
in this Third Amendment.

     NOW,  THEREFORE,  in  consideration  of the premises and mutual  agreements
contained herein and for other good and valuable consideration,  the receipt and
sufficiency  of which are  hereby  acknowledged,  the  parties  hereto  agree as
follows:

                                    ARTICLE I

                         AMENDMENTS TO MERGER AGREEMENT

     1.1 The Merger  Agreement  hereby is amended by deleting  therefrom  in its
entirety Section 1.1 of the Second Amendment.




     1.2 Section  10.1(d) of the Merger  Agreement (as amended by Section 1.6 of
the Second  Amendment)  hereby is amended  by  deleting  the words "on or before
March 4, 1996", and adding the words "on or before March 13, 1996" at the end of
such section.

     1.3 Section  6.7(b) of the Merger  Agreement  (as amended by Section 1.3 of
the  Second  Amendment)  hereby  is  amended  by  deleting  clauses  (x) and (y)
therefrom  in their  entirety  (but not  deleting  the  proviso  following  such
clauses),   and  substituting   therefor  the  following:   "(x)  is  less  than
$80,000,000,  TFC shall pay to Shared  Technologies  an amount in cash  equal to
such difference or (y) is more than $80,000,000 Shared Technologies shall pay to
TFC an amount in cash equal to such difference;".

                                   ARTICLE II

                        PROVISIONS OF GENERAL APPLICATION

     2.1 Except as otherwise expressly provided by this Third Amendment,  all of
the terms,  conditions and provisions to the Merger Agreement remain  unaltered.
The Merger Agreement and this Third Amendment shall be read and construed as one
agreement.

     2.2 If any of the  terms of this  Third  Amendment  shall  conflict  in any
respect with any of the terms of the Merger  Agreement,  the terms of this Third
Amendment shall be controlling.

     IN WITNESS WHEREOF,  the parties hereto have caused this Third Amendment to
be executed by their duly authorized officers,  all as of the day and year first
above written.

SHARED TECHNOLOGIES INC.                               THE FAIRCHILD CORPORATION


By: /s/ Anthony D. Autorino                            By: /s/ Donald E. Miller
    -----------------------                                --------------------
    Chief Executive Officer                                Senior Vice President
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FAIRCHILD INDUSTRIES, INC.                             RHI HOLDINGS, INC.


By: /s/ Donald E. Miller                               By: /s/ Donald E. Miller
    --------------------                                   --------------------
    Vice President                                         Vice President

ACCEPTED AND AGREED TO BY:


FAIRCHILD HOLDING CORP.


By: /s/ Donald E. Miller
    --------------------
    Vice President

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