The boards of both companies have approved the deal which, if regulators give it the go-ahead, will create a new company worth $327 billion by the end of the year.
Simpson Thacher & Bartlett's corporate partners Richard Beattie and Peter Ruegger and associate Peter Malloy are providing counsel for AOL.
The firm was reportedly invaded over the weekend by AOL executives and bankers from Salomon Smith Barney who set up computers in conference rooms to go through the mountains of data to see if the combination was viable.
New York's Cravath Swaine & Moore's corporate partners, Robert Kindler and Faiza Saeed, litigation partner Robert Joffe, and tax partner Lewis Steinberg are working on the deal for Time Warner.
One of the Cravath Swaine lawyers is understood to have been dragged back from holiday in Antigua to hammer out the final details.
AOL senior vice president and general counsel is Paul Cappuccio. Vice president and associate general counsel is Michael McGowan.
Time Warner executive vice president and general counsel is Christopher Bogart. Spencer Hays is senior vice president and deputy general counsel, and Ed Weiss is vice president and associate general counsel