The company, which owns Borsa Italiana and the London Stock Exchange, said discussions with Deutsche Boerse were ongoing over a potential merger which would create substantial revenue and cost benefits.
LSE and Deutsche Boerse said last week they were in merger talks, although New York Stock Exchange owner Intercontinental Exchange has raised the prospect of a bidding war by saying it is considering making a counter-offer.
Adjusted pre-tax profit rose to £643.4m from £491.7m pounds a year earlier.
Revenue rose 78 per cent to £2.28bn. Revenue includes both continuing and discontinued operations and excludes unrealised gains and losses for 2014 at LCH.Clearnet.
Analysts had forecast on average full-year pre-tax profit of £589.01m. Revenue fell short of forecasts for £2.4bn.
The company proposed a higher final dividend of 25.2p per share, implying a 20 per cent increase in the dividend for 2015.