ExxonMobil, the world's largest company by revenue, now stands alone in not offering protections to gay and lesbian workers in the Fortune 50, and GMAC has that distinction in the Fortune 100.

A new report released Wednesday by the Philadelphia-based Equality Forum shows a seismic shift from a majority (64.6%) to near universal (94.2%) adoption of sexual orientation nondiscrimination policies in the Fortune 500 since the fall of 2003.

“The Fortune 500 have overwhelmingly decided that including sexual orientation is in the best corporate interest and helps communicate corporate values to the estimated $660 billion annual GLBT consumer market,” said Equality Forum Executive Director Malcolm Lazin in a press release.

This year marks the fifth year the group has polled Fortune 500 companies about gay protections. Equality Forum worked alongside Professor Louis Thomas of the Wharton School and Professor of Law Ian Ayres of the Yale Law School.

ExxonMobil remains the only Fortune 50 company that does not specifically provide sexual orientation protections. At the company's 2008 shareholder meeting, a record number of shareholders (40%) voted in favor of adding sexual orientation and gender identity to the company's official employment policy, despite opposition by ExxonMobil management.