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                                  Exhibit (15)




October 29, 1999



USG Corporation
125 South Franklin Street
Chicago, Illinois  60606



Gentlemen:

We are aware that USG Corporation has incorporated by reference into previously
filed Registration Statement Numbers 33-40136 and 33-64217 on Form S-3 and
33-22581, as amended, 33-22930, 33-36303, 33-52573, 33-52715, 33-63554, and
33-65383 on Form S-8 its Form 10-Q for the quarter ended September 30, 1999,
which includes our report dated October 14, 1999, covering the unaudited
condensed financial information contained therein. Pursuant to Regulation C of
the Securities Act of 1933, these reports are not considered a part of the
registration statement prepared or certified by our firm or reports prepared or
certified by our firm within the meaning of Sections 7 and 11 of the Act.


Very truly yours,

/s/ ARTHUR ANDERSEN LLP


ARTHUR ANDERSEN LLP





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