Herbert Smith has completed its first significant deal for Co-operative Financial Services (CFS) since being appointed to its legal panel in November.

The top 10 City firm has advised CFS on an IT outsourcing agreement with technology company Xansa, worth about £100m over five years. Around 220 CFS employees will transfer to Xansa as part of the agreement.

Xansa will take on the application development and maintenance for all of CFS' banking, insurance and Smile internet banking businesses' IT platforms.

Technology, media and telecoms partner Mark Turner led the Herbert Smith team advising CFS on the deal, which closed at the end of March. He worked alongside CFS in-house lawyers Esther Stevens and Chris Parsons.

Herbert Smith was appointed to the first joint panel of the Co-op and CFS late last year alongside national firms Eversheds, Hammonds, Watson Burton and Addleshaw Goddard.

Turner told Legal Week: "The deal itself was interesting because there was already an existing relationship between CFS and Xansa on the banking side but they wanted someone to run insurance and banking. We were replacing a long-established relationship with a wider and deeper one."

Herbert Smith's outsourcing practice has advised on deals including the £486m outsourcing agreement between life insurer Pearl Group and Tata Consultancy Services and the agreement between InBev and LogicaCMG.

Xansa did not use any external advisers with in-house lawyer Charles Lilley leading on the transaction.