Investment bankers in the oil industry haven't been too busy of late. There wasn't a single corporate oil deal announced in the fourth quarter, and the first quarter didn't seem like it would be much better.

But the outlook changed on March 23, when Canada's Suncor Energy Inc. announced it had agreed to buy rival Petro-Canada Ltd. for C$19.2 billion ($15.5 billion), creating Canada's largest oil and gas company. Not only was it the fifth-largest global M&A transaction so far this year, it was the largest in the oil industry since Norsk Hydro ASA's merger with Statoil ASA to form StatoilHydro ASA in 2006; the sixth-largest Canada-targeted M&A transaction ever; and the 10th-largest oil and gas M&A deal ever, according to research firm Dealogic. Oil and gas-targeted M&A volume is now at $33.5 billion -- still down 29% against the $47.4 billion that was recorded at this time last year.

In Suncor's corner were CIBC World Markets Inc.'s Paul Spafford, Art Korpach, Mike de Carle and Shane Popowich, along with Morgan Stanley's Mark Horsfall, Jeff Hogan, Steve Escaler and Joe Rault III.

CIBC's Spafford has done other big Canadian deals, although not necessarily in energy. He advised telecom BCE Inc. on its $48 billion leveraged buyout in 2007 (which was eventually scrapped), as well as Toronto-based miner Inco Ltd. on its $17.6 billion acquisition of Falconbridge Ltd. and its $35.9 billion acquisition by Phelps-Dodge Corp. in 2006. He also advised Westcoast Energy Inc. on its $8.5 billion purchase by Duke Energy Corp. in 2001. Morgan Stanley's Horsfall, meanwhile, advised Calgary oil and gas explorer Provident Energy Trust on the sale of its 96% stake in Los Angeles oil and gas producer BreitBurn Energy Partners LP to a private equity and management consortium last year for $305 million.

For deal advice, Petro-Canada tapped RBC Capital Markets Corp.'s Mike Norris, Gord Ritchie, Brad Cameron, Paul Hand and Trevor Gardner as well as Deutsche Bank AG's Tom Barber, Bob Jeffe, Jonathan Cox and Mike Hill. In February, RBC's Norris advised Nova Chemicals Corp. on its acquisition by Abu Dhabi state-owned International Petroleum Investment Co. for $2.3 billion. Deutsche Bank's Cox last year advised Canada's Precision Drilling Trust on its acquisition of Grey Wolf Inc. of Houston for $2 billion.

On the legal side, Blake, Cassels and Graydon LLP's Brock Gibson and Dan Fournier are counseling Suncor, while Macleod Dixon LLP's Bob Engbloom and Justin Ferrara and Torys LLP's Peter Jewett and Patrice Walch-Watson are assisting Petro-Canada.

This is the second deal announced for Blake's Gibson in as many months. He counseled Dana Petroleum plc on its $346 million acquisition of Canada's Bow Valley Energy Ltd. in February. He also advised Grey Wolf on its acquisition by Precision Drilling last year, working across from Deutsche Bank's Cox.

Macleod's Engbloom advised Canadian oil services provider CCS Income Trust when it was taken private by a group led by its CEO in 2007 for C$3.5 billion. And Torys' Jewett represented Ottawa-based business intelligence software maker Cognos Inc. on its sale to IBM Corp. in 2007 for $5 billion. He also worked on the Westcoast acquisition by Duke with CIBC's Spafford.