The rekindled merger discussions between United Airlines Inc. parent UAL Corp. and US Airways Group Inc. has prompted lots of speculation, including about who is advising the two airlines. Where to start? By looking at the firms and people who counseled the companies on previous transactions, including when they agreed to combine a decade ago in a deal that was eventually scotched by the Department of Justice.

Both airlines have changed managements and have been through Chapter 11 since then, and US Airways was effectively sold. But both have long relationships with various dealmakers.

For example, Timothy Pohl, Peter Krupp and Sean Doyle of Skadden, Arps, Slate, Meagher & Flom LLP advised America West Holdings Corp. on its 2005 acquisition of US Airways out of bankruptcy, after which the America West management team took control of the company. The same trio also counseled US Airways on its failed bid to buy Delta Air Lines Inc. out of bankruptcy in 2006. And Skadden's Peter Atkins represented US Airways on its 2000 agreement with UAL. Charles "Rick" Rule and Deborah Garza, then of Fried, Frank, Harris, Shriver & Jacobson LLP, were antitrust counsel on the Delta bid.

Rule has since moved to Cadwalader, Wickersham & Taft LLP, Garza to Covington & Burling LLP.

On the banking side, US Airways used Citigroup Inc. on the Delta bid and its subsidiary Salomon Smith Barney on the 2000 agreement to merge with UAL. Jeffrey Buckalew of Greenhill & Co. advised America West on the US Airways acquisition. UAL may well be using Cravath, Swaine & Moore LLP, its longtime outside counsel, on its latest US Airways talks. Cravath's Allen Finkelson and Scott Barshay advised on the 2000 deal with US Airways, and the firm worked for UAL on its 2008 joint venture with Continental Airlines Inc.

The Air Line Pilots Association used Robert Fleder and Carl Reisner of Paul, Weiss, Rifkind, Wharton & Garrison LLP on the original UAL-US Airways deal. ALPA used Robert Davis of Cleary Gottlieb Steen & Hamilton LLP on Delta's 2008 acquisition of Northwest Airlines Corp.