Irish bookmaker Paddy Power said the growth in the company's sportsbook has picked up after a couple of drab months at the start of the year.Trading in the first two months of 2009 was hit by a number of race meeting cancellations, but since then business has picked up, due in part to the expansion of the bookie's online business outside Ireland.A number of recent big betting sporting events have produced unfavourable results for the company but there is some consolation in the trend for successful punters to reinvest a higher proportion of their winnings.As a result of the unhelpful sporting outcomes, the sportbook's gross win percentage in 2009 has been below the management's expectations in the non-retail channel, with telephone punters proving a bit too clued up for the company's comfort.In the 19 weks to 12 May, the non-retail sportsbook amounts staked have grown by 31% on a constant currency basis, while the retail side has seen growth of just 1%.Gaming and machine gross win has grown by 9%.The group said it remains comfortable with the market's current expectations for full-year profits. In a separate announcement, the company said it has acquired a 51% stake in Australian bookmaker Sportsbet.Initially Paddy Power will pay A$48.5m (€27.2m) for Sportsbet, consisting of A$45.8m in cash, with the rest to be satisfied through the issue of 100,000 Paddy Power shares to Sportsbet shareholders.Sportsbet expects earnings before interest, tax, depreciation and amortisation (EBITDA) in the year to 30 June 2009 to be A$14.6m.An additional cash consideration of A$10m will be payable in early 2010 if the EBITDA of Sportsbet in calendar 2009 is higher than A$16.5m.