LONDON - London will be packed during the summer Olympics as the number of overseas visitors rises and Britons postpone holiday plans to stay home for the games, a study said on Wednesday.

The number of tourists from abroad is expected to be 13 percent higher than last summer, with a quarter of visitors coming from North America, research by travel bookings group Amadeus found.

The number of Britons flying abroad in the three weeks before the Opening Ceremony on July 27 is expected to be five percent down on the same period last year.

But the number leaving in the three weeks after the Olympics end on August 12 is set to be 10 percent higher than the same time last summer.

Across the whole summer (calculated from July 2 to September 2), two percent fewer Londoners will leave the city than in 2011.

A spokesman for Spanish group Amadeus told Reuters: "The predictions that Londoners would flee the city during the Olympic Games were perhaps a little premature."

Their figures are based on global air reservations through all online and offline travel agencies, but not direct bookings, which make up 50 percent of bookings.

The research is good news for London's tourist industry, which had feared that a reduction in traditional tourists and an exodus of Britons would offset Olympics arrivals.

Last November, the European Tour Operators Association said it was seeing an average 90 percent downturn in bookings to Britain from the rest of Europe over the Olympic period.

The Amadeus data was gathered by ForwardKeys.com and can be viewed in more detail at http://www.forwardkeys.com/revenue-management/article/London-Olympics-Inbound-Impact.html?