* Raises profit forecast to 310-320 mln stg from 280-300 mln
* Passenger numbers up 7.1 pct to 58.4 mln in year to end Sept
* Shares up nearly 4 pct
By Rhys Jones
LONDON, Oct 3 (Reuters) - British low-cost airline easyJet's profits got an unexpected boost from sun-starved Britons taking last-minute holidays to flee the wet weather at home this summer and from Londoners getting away after the Olympics.
Europe's second-largest budget airline after Ryanair said on Wednesday it now expects to report a pretax profit of between 310 million and 320 million pounds ($516.43 million) for the year to the end of September, having previously predicted a result of 280 million to 300 million pounds.
"Following the end of the Olympic games demand from London increased towards the upper end of expectations with the late market and beach routes performing particularly well," said Chief Executive Carolyn McCall, adding that the carrier was "well placed to continue to succeed" despite a European economic outlook which she called "highly uncertain".
EasyJet, the largest carrier at London's Gatwick airport, said a strong rise in summer bookings from Britain to Malaga and Alicante in Spain and Faro in Portugal had helped revenue per seat by as much as 5.5 percent in the last six months. Annual passenger numbers rose by 7.1 percent to 58.4 million.
Some 40 percent of easyJet's flights are to or from Britain, with around a quarter of its 193 plane fleet based at Gatwick.
EasyJet said its performance on routes within mainland Europe also improved during the year, helped by growth on Swiss services and the addition of French regional services.
Shares in easyJet, which have risen 50 percent in 2012, were up nearly 4 percent at 615.5 pence by 0823 GMT, valuing the group at around 2.5 billion pounds.
Profits have doubled since McCall took over as chief executive in July 2010.
"McCall's second full year in charge has delivered another impressive increase in profits. That's no mean feat in view of the oil price," said Charles Stanley analyst Douglas McNeill.
Prior to Wednesday's announcement analysts on average expected the airline to report a full-year pretax profit of 294.4 million pounds, according to Thomson Reuters I/B/E/S Estimates.
EasyJet's strong performance bucks tough conditions elsewhere in the airline sector
European carriers, including Air France-KLM and Lufthansa, have seen recent results hit by a toxic mix of high fuel costs, weak consumer confidence and the eurozone crisis.
Since the start of the year airlines including loss-making Spanair and Hungarian flag-carrier Malev have ceased operations, leaving gaps in the market that low-cost competitors have been quick to exploit.
EasyJet said strict allocation of capital and aircraft across its network, improvements in revenue management and a tight control of costs had helped it absorb an additional 230 million pounds in fuel costs this year.
At current fuel and exchange rates the budget carrier, which has already bought 77 percent of the fuel it needs for next year, expects its 2012/13 fuel bill to rise by up to 40 million pounds.
The carrier said second half costs per seat were likely to rise by between 1.5 and 2 percent, excluding fuel.
A third of seats in the first quarter of its new fiscal year had already been sold, the airline said.�