Serco is confident enough about prospects to repeat forecasts for 2009 ahead of meetings with analysts prior to its financial year end on 31 December.The outsourcing group predicts double-digit revenue growth this year and a 30 basis point increase in adjusted pre-tax profit margin, excluding SI International which should increase growth by some 10%.Including the benefit of SI International, it's thought adjusted operating profit margin of 5.3% in 2008 will rise 40bps in 2009.'We remain on track to deliver on our financial guidance for 2009, and continue to see further potential opportunities in both existing and new markets," Serco said Tuesday.In February, it forecast revenue would increase to about £5bn and adjusted operating profit margin to 6.3% by the end of 2012, excluding material acquisitions, disposals and currency effects.Full year results will be published on 26 February.