The Way Back Machine can’t verify this but a very long list from 2009 at Human Rights -
http://www.yourchristianspace.com/blog/view/id_18489/title_top-companies-that-support-gay-rights/
It’s easier to list those who don’t support sodomy.
http://www.businessinsider.com/major-brands-that-support-gay-marriage-photos-2013-3?op=1
Bud Light
Martha Stewart
Paula Deen
HBO’s True Blood
Smirnoff’s
Absolut
Kenneth Cole - shoes
Nordstrom dept store
American Apparel
And - http://ceoworld.biz/ceo/2012/07/02/list-of-companies-that-support-gay-marriage :
Allstate
Applebee’s
Best Buy
Clorox
Costco
Delta Airlines
Ford
General Motors
Gerber Baby Products
Hilton Hotels
Home Depot
IBM
McDonald’s
Olive Garden
Proctor & Gamble
Red Lobster
Rite Aid
Sears
Southwest Airlines
State Farm
United Airlines
UPS
Walgreens
Walt Disney