Betfair Group reported first half core earnings at the top end of expectations, driven by a good start to the football season for the world's largest betting exchange and rises in the number of customers and the value of bets.

Betfair, founded 10 years ago by one-time professional gambler Andrew Black and former JP Morgan trader Edward Wray, said underlying earnings before interest, tax, depreciation and amortisation (EBITDA) rose 36 percent to 42.4 million pounds in the six months to October.

That was ahead of an average forecast of 37.4 million based on a poll of 10 analysts supplied by the company.

Betfair generated core revenue growth of 12 percent year-on-year in the second quarter, and it has risen 13 percent so far in the third quarter. Group revenue rose 1 percent to 191.3 million pounds in the first-half.

These results were driven by an excellent exchange performance following a very positive start to the football season and improved monetisation of activity, said departing chief executive David Yu in a trading statement on Wednesday.

The group added in a separate statement that it has appointed Chief Financial Officer Stephen Morana as interim chief executive.

Yu is stepping down at the end of the month with former Paddy Power Chief Operating Officer Breon Corcoran already named as his permanent replacement starting in August.

Betfair is not a traditional bookmaker but instead acts as an intermediary between gamblers wanting to place a bet or offer odds to others, taking a commission on their winnings

Shares in Betfair, which have dived from 1,610 pence shortly after its flotation last October, closed at 813 pence on Tuesday, after climbing over 7 percent in the past month and valuing the group at approximately 820 million pounds.

(Reporting by Lorraine Turner; Editing by Paul Hoskins)