FTSE 250 technology company Misys has handed general counsel Tom Kilroy a role on the company's board as acting CEO amid £2bn merger negotiations with Swiss rival Temenos.

Misys announced the appointment on 8 February after former chief executive Mike Lawrie's resignation from the company. Kilroy (pictured) has taken over the CEO role with immediate effect, although Lawrie will remain at Misys until 31 March this year.

The appointment of an in-house lawyer to a senior management role is a rare occurence at major companies, with high-profile examples in recent years including UBS GC Peter Kurer, who was named chairman of the Swiss bank in 2008, and former Davis Polk & Wardwell M&A lawyer Tom Glocer, who was appointed group CEO of Reuters in 2001.

Kilroy has been GC at Misys since August 2009 when he joined from GE Healthcare, where he was EMEA GC. He has also spent time in private practice at legacy Hammond Suddards after training at Farrer & Co.

The appointment comes after Misys and Swiss banking software company Temenos agreed the key terms of their proposed merger, which is set to see the combined entity become the world's largest supplier of risk management computer software to banks.

Allen & Overy is advising longstanding client Misys with a team led by City corporate partners George Knighton and Jeremy Parr, while Herbert Smith is acting for Temenos led by London corporate partner Will Pearce. Switzerland's Homburger is also acting for Temenos led by corporate partner Dieter Gericke.

Under the key terms of the merger, Misys shareholders will retain 53.9% of the combined group and Temenos 46.1%. The companies are intending to merge under a new holding company and list on the London Stock Exchange, with a potential secondary listing on the SIX Swiss Exchange.

Tom Kilroy is the author of the GC's Eye View blog. Click here to follow Tom on Twitter.