Gibson left British Energy last April after four years, without a new role lined up (PRWeek, 27 April 2007).
Previously he was the director of regulation and public policy at Energis, the telecoms and internet company that was acquired by Cable & Wireless. He has more than 15 years' experience in the communications industry.
Misys is performing well financially and last month said it had experienced a £60m increase in net profits in the six months to 30 November 2007.
'My experience of company turnarounds puts me in good stead for the challenge ahead,' said Gibson.