Warren's appointment comes as the UK banking-to-healthcare software group announces a clear-out of top executives in an effort to restore the fortunes of the struggling business.

Howard Evans, finance director, is to leave at the end of the year, while Tom Skelton, head of healthcare, has quit the board and been replaced for an interim period by new recruit Paul Lewis.

Jasper McMahon, corporate development director, has also left with immediate effect.

The boardroom shake-out has been overseen by new CEO Mike Lawrie, who took over the reins last year following the resignation of long-time chairman and chief executive Kevin Lomax in the wake of a failed management buy out.

Shares in the vendor moved up 5.6 per cent to 238.8p as investors welcomed the changes and cheered signs of recovery in the core banking systems business as the company reported its half-yearly results.

First half revenue across the group was £468 million pounds, little changed from £465 million a year ago. But while the healthcare division saw revenues fall to £147 million - a performance described by Lawrie as "unacceptable" - the banking business saw revenue rise to £133 million pounds from £125 in the first half of 2005.

Says Lawrie: "Our treasury & capital markets business is growing well as a result of its revamped product portfolio and core banking is making some progress."

Lawrie says he will lay-out turnaround plans in March, but has warned that it may take three-to-five years to get the company back on its feet.

At core banking, Warren takes over from acting CEO James Cheesewright. Cheesewright will take up a new senior PLC role in March when Warren takes up his position.

Says Warren: “I am joining Misys at an exciting time. The banking industry is experiencing good growth, which is forecast to continue. Aligned to this, banks are increasingly looking for a solutions-based approach."