The LSE has fought off several takeover approaches

Pre-tax profits for the year to 31 March jumped 73% to �161.5m ($320.7m), while operating profits rose by a better-than-expected 55% to �185.6m.

LSE chief executive Clara Furse said it was an "outstanding performance" and added that trading remained strong.

The LSE has fended off four bid approaches in the past two years.

Trading remains strong with positive momentum carrying forward into the current financial year Clara Furse, London Stock Exchange chief executive See the LSE's share price

Most recently, in February the LSE saw off a hostile bid approach from the US exchange Nasdaq, describing the US suitor's 1,243 pence-per-share offer as "wholly inadequate".

The LSE's shares closed 19 pence or 1.5% higher in London at 1,311p.

The LSE said that it enjoyed strong activity on its main market during the past year, with 503 new issues and the total amount of money raised by new and further issues up 57% to �53.7bn.

The number of trades on its electronic order book, SETS, rose 58% to 353,000 a day.