US firms' Paris offices have dominated the lead roles on the $3.1bn (£1.66bn) merger of Compagnie Generale de Geophysique (CGG) and Veritas DGC, creating the world's largest fossil fuel field surveyor.

Willkie Farr & Gallagher, Skadden Arps Slate Meagher & Flom and Linklaters advised Paris-based acquirer CGG, while Vinson & Elkins and Paul Hastings Janofsky & Walker advised Houston-based Veritas. Both Veritas and CGG provide services, data and equipment to the oil and gas exploration industry.

Willkie Farr advised CGG on the French side and competition aspects of the acquisition, under a team led by Laurent Faugerolas, with Skadden New York corporate partner Peter Atkins acting as US counsel.

Paris-based capital markets partner Tom O'Neill led the team for Linklaters, which advised on the financing and US law aspects of the acquisition. Goodmans acted as Canadian counsel for CGG.

O'Neill commented: "The agreement of two out of the five global participants to merge their businesses clearly transforms CGG and the industry."

Vinson Houston corporate partner Jeffery Floyd advised Veritas on US aspects, with Paul Hastings Paris chair Dominique Borde advising on local law.

Cravath Swaine & Moore advised Credit Suisse as lead arranger, with Dewey Ballantine advising the financial services group in its role as financial adviser to CGG.

The deal comes as a rising demand for crude oil has led to prices jumping around 80% in the last three years, spurring a demand for exploitation services as producers seek new sources.

The merged company, known as CGG-Veritas, will create a surveying giant with 20 vessels and around 7,000 staff. The transaction is expected to be completed in the closing months of 2006.