LONDON (Reuters) - Rolls-Royce expects to deliver good growth in full-year profit, despite lowering revenue guidance for its marine division, which has been hit by changes to the timing of some deliveries.

Rolls, the world's second-largest maker of aircraft engines behind U.S. group General Electric , on Friday said trading since July had been robust and that it continued "to expect good growth in underlying (annual) revenue and profit, with cash flow around breakeven".

Rolls-Royce is expected to post an average 2012 pretax profit of 1.38 billion pounds ($2.20 billion), according to a Thomson Reuters I/B/E/S poll of 16 analysts.

The predictions underscore soaring demand for narrowbody or single-aisle jets. Analysts forecast that 20,000 narrowbody planes will be produced in the next 20 years.

Europe's Airbus and U.S. rival Boeing are ramping up output and are targeting more than 1,100 deliveries this year.

Rolls said guidance for all of its business segments remains unchanged, except for its marine unit where it expects full-year sales to be broadly flat due to "the phasing of deliveries".

Shares in Rolls-Royce, which have risen 18 percent this year, closed at 863.50 pence on Thursday, valuing the group at around 16 billion pounds.

(Reporting by Rhys Jones; editing by Paul Sandle)