News Release
                                                     USG Corporation
                                                     For Immediate Release
Corporate Communications
(312) 606-5635
Investor Relations Department
(312) 606-4125
PR #98-04

               USG CORPORATION UPDATES SHARE PURCHASE RIGHTS PLAN

CHICAGO,  March 27,  1998 -- USG  Corporation  (NYSE:  USG) today  approved  the
redemption of its current share purchase rights and adopted a new share purchase
rights  plan  that is  designed  to  continue  the  assurance  of fair and equal
treatment of all  shareholders in the event of any proposed  takeover.  The plan
involves  the  distribution  of one  purchase  right for a new  series of junior
preferred stock for each outstanding share of the company's common stock.

USG will redeem the current  preferred  share purchase  rights  declared under a
10-year rights agreement adopted in May 1993. A redemption  payment of $0.01 per
share of USG  Corporation  common stock will be  distributed  on May 1, 1998, to
holders of record as of April 15,  1998.  According  to William C. Foote,  USG's
chairman and chief  executive  officer,  "The old rights plan is being  replaced
because it no longer  adequately  reflects the prospects and market value of the
company."

"The new rights plan is designed to strengthen previous provisions aimed at fair
and equal treatment for all  shareholders in the event of any proposed  takeover
of your company and to help maximize shareholders' long-term investment in USG,"
continued  Foote. "It guards against partial tender offers,  squeeze-outs,  open
market  accumulations  and other tactics to gain control of the company  without
paying all shareholders an adequate premium value."

Foote added,  "The rights are not being distributed in response to any effort to
acquire the company, and the board is not aware of any such effort. However, if
at any point in the future  another  party became  interested in such an effort,
the plan would  encourage it to negotiate with USG's board of directors prior to
attempting a takeover."

As a response to unwelcome  takeover tactics,  the rights plan allows holders of
rights to purchase  shares in either USG  Corporation  or an acquiring  party at
discounts  from market  value,  or permits USG to exchange  common stock for the
rights. The plan has four basic provisions.

First,  if an acquiror  buys 15 percent or more of USG's stock,  the plan allows
other  shareholders  to buy,  with each  right,  additional  USG  shares at a 50
percent  discount.  Second,  if USG is  acquired  in a merger or other  business
combination  transaction,  rights  holders will be entitled to buy shares of the
acquiring company at a 50 percent  discount.  Third, if an acquiror buys between
15 percent and 50 percent of USG's  outstanding  common  stock,  the company can
exchange  part or all of the rights of other holders for shares of the company's
stock on a one-for-one  basis, or shares of the new junior  preferred stock on a
one-for-one-hundredth  basis. Fourth, before an acquiror buys 15 percent or more
of USG's common stock,  the rights are  redeemable for one cent per right at the
option of the board of directors. This provision permits the board to enter into
an  acquisition  transaction  that is  determined  to be in the best interest of
shareholders.  The Board is authorized to reduce the 15 percent threshold to not
less than 10 percent.

The new rights plan will become  effective on April 15, 1998, and will expire on
March 27, 2008. The rights distribution is not taxable to shareholders.

USG  Corporation  is a Fortune 500  company  with  subsidiaries  that are market
leaders in their key  product  groups:  gypsum  wallboard,  joint  compound  and
related  gypsum  products;   ceiling  tile  and  grid;  and  building   products
distribution.  For more information  about USG  Corporation,  visit the USG home
page at http://www.usg.com.

Linda M. Novak, Manager, Corporate Communications
James R. Bencomo, Director, Investor Relations

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