Sullivan & Cromwell, Freshfields Bruckhaus Deringer and Slaughter and May have taken lead roles on the £1.7bn takeover of UK IT services company Logica by Canadian rival CGI.

Sullivan took the lead role for the acquirers, fielding a team led by European M&A head Tim Emmerson and fellow corporate partner Ben Perry.

The US firm's team also included lawyers in its New York, Paris and Frankfurt offices, with City partners Juan Rodriguez, Michael McGowan and Presley Warner advising on antitrust, tax and finance respectively.

The Sullivan team won the mandate through a recommendation by Goldman Sachs, a regular client for UK M&A matters.

Freshfields, meanwhile, acted for longstanding client Logica on the deal, which will create a global IT business. The magic circle law firm fielded a team under corporate partner Andrew Hutchings alongside corporate partner David Sonter and employment partner Simon Evans.

Slaughters corporate finance partner William Underhill advised Goldman on cash confirmation aspects of the takeover, while Norton Rose employee benefits and compensation partner Monique Fry is also advising CGI.

Emmerson (pictured) commented: "The cross-border aspect of a deal like this always adds interest and this transaction was no exception, requiring reconciliation of expectations about both deal execution and also conflicting legal constraints."

Other recent M&A mandates handled by Sullivan's London arm this year include Brait Capital's $2.45m (£1.6m) buyout of Iceland Foods and Silver Lake Partners' multibillion-dollar sale of Skype to Microsoft.