In April, Fidessa agreed to a 1.5 billion-pound ($2.1 billion) acquisition by Ion, a financial software firm backed by U.S. private equity group Carlyle, ditching a takeover by Swiss banking software business Temenos.

Fidessa, which listed on the London Stock Exchange in 1997, provides software and services for investment management systems, analytics and market data, serving both the buy-side and sell-side. Its products include an order management system for equity markets.

Fidessa's takeover comes during a wave of deal-making in Britain, as companies take advantage of cheap debt to pursue mergers and acquisitions.

(Reporting by Sangameswaran S in Bengaluru; Editing by Sai Sachin Ravikumar)