The unsolicited bid values each London Bridge share at 95 pence, a generous 54% premium over Friday's closing price of 61.5 pence, but well down on the firm's £64 per share dotcom bubble valuation. Fair Isaac says the offer has been irrevocably accepted by London Bridge founder and chairman Gordon Crawford and fellow directors who own 46.2% of the firm's share capital.

Operating profit at London Bridge nudged above break-even to £329,000 for the year-ended 31 December 2003, against losses of £48.3 million in 2002, including £35.9m in goodwill impairment from headcount reductions and consolidation of US operations.

Crawford will continue to work with the enlarged group through a consultancy arrangement for a period of 12 months. Jon Lee and Gordon Stuart, London Bridge CEO and group finance director will stay in their current roles.

Crawford says Fair Isaac is not only gaining a strong platform to develop its UK and European business but also to reinforce its position in the US.

"Customers of both companies will have access to a broader range of products and services across the entire origination through to collections and recoveries cycle," he says.

Commenting on the offer, Tom Grudnowski, CEO of Fair Isaac, says: "The acquisition of London Bridge fits clearly within Fair Isaac's strategy of adding other mission-critical vertical applications to its existing portfolio of analytics applications and decision management solutions. Our businesses are highly complementary and we expect the acquisition of London Bridge to create benefits for both companies' customers and employees."

Once the offer is declared unconditional, London Bridge will delist from the London Stock Exchange and be re-registered as a private company.