Richard Chandler Jr., executive vice president, chief legal officer and secretary of Chicago Bridge & Iron Co., turned to Wachtell, Lipton, Rosen & Katz to negotiate a definitive agreement for the engineering and construction company to acquire The Shaw Group Inc. for about $3 billion.

Shaw Group, based in Baton Rouge, La., is using lawyers from Vinson & Elkins of Houston and Jones, Walker, Waechter, Piotevent, Carrere & Denegre of New Orleans in the deal that was announced on July 30.

Terms of the acquisition call for CB&I, which is based in The Woodlands, to acquire Shaw for $46 per share in cash and stock. The acquisition has been unanimously approved by both companies’ boards of directors and is subject to approval by their shareholders, along with certain regulatory approvals and customary closing conditions.

The acquisition is expected to close in early 2013. The deal calls for CB&I to operate Shaw as a business sector called CB&I Shaw.

Corporate partners Daniel Neff and David Shapiro of New York City lead Wachtell’s team representing CB&I on the deal. Others from Wachtell, all of New York, are corporate associates Scott Golenbock and Kendall Fox; antitrust partner Nelson Fitts and associate Franco Castelli; executive compensation and benefits partner David Kahan and associate Adam Kaminsky; restructuring and finance partner Eric Rosof and associates Austin Witt and John Sobolewski; and tax partners T. Eiko Stange and Joshua Holmes.

V&E partner Keith Fullenweider of Houston leads the mergers and acquisitions team assisting Shaw Group, a longtime V&E client. Other M&A lawyers from V&E, all of Houston, include partners Jeffery Floyd and Stephen Gill and associates Lande Spottswood, James Garrett, John Rosenkild and Christopher Colquitt.

V&E capital markets partner David Oelman of Houston, Shaw’s primary outside counsel, is working on securities and governance matters, along with V&E associate Julian Seiguer of Houston.

Other V&E lawyers include employee benefits partner Brian Bloom of Dallas and associate Jared Whalen of Houston; debt capital markets partner David Stone of Houston; government contracts partners Suzanne Reifman and David Johnson and associate Jamie Tabb of Washington, D.C.; labor and employment partner Thomas Wilson and associate Christie Alcala of Houston; antitrust partners William Vigdor and Dionne Lomax of D.C.; tax partner John Lynch of Houston; finance partner William Bos and associate Guy Gribov of Houston; litigation partner Michael Holmes of Dallas; and environmental partner Larry Nettles of Houston.

The Jones Walker lawyers for Shaw are led by corporate partner Scott Chenevert of Baton Rouge, with assistance from corporate special counsel Richard Wolfe of New Orleans and Baton Rouge-based associates Alexandra Layfield and Charles Reeves; antitrust partners David Radlauer and Mark Cunningham of New Orleans; and tax partner Arnold Havens and special counsel Michael McDonald of D.C.