British budget airline easyJet said rising fuel costs sent first-half losses up threefold to GBP57.5 million pounds (USD$112.9 million), but that summer bookings were ahead of last year.

The company, Europe's fourth biggest airline, reiterated an earlier warning that record fuel costs would erode full-year profit if they continued to rise, but that demand from its passengers remained strong.

"We are seeing no sign in reduction in discretionary air travel... Maybe people are choosing airlines more selectively, but we are seeing no fall off in weekend breaks, no change in bookings," Chief Executive Andy Harrison told reporters on Wednesday.

He said the Luton-based airline was run more efficiently than many of its rivals, which he predicted would fail to survive in the current high cost environment and should not hope to be rescued by easyJet.

"It's hard to understand why we would want to buy weak airlines with old aircraft. We'd be happy to wave goodbye," Harrison said.

However, Collins Stewart analyst Andrew Fitchie said the airline was not immune to an economic downturn.

"Consensus is only currently modeling the impact of increased fuel costs; a material economic slowdown is not being discounted and we believe this represents a further risk to the airlines and low cost carriers in particular," he said.

EasyJet reported a 15 percent growth in first half passenger numbers to 18.9 million, of which just 2.5 percent was attributed to last year's acquisition of GB Airways. The load factor held steady at 81 percent.

Harrison said high fuel prices -- driven by the rising price of oil -- remained the firm's biggest challenge.

"The price of jet fuel has risen 35 percent over the last three months and is now 80 percent higher than last year," he said.

If fuel averaged around USD$1000 a tonne it would increase the company's bill by GBP45 million pounds in the second half, he said. It is currently around USD$1100-USD$1150 a tonne.

The company, Europe's second biggest budget carrier in terms of passengers behind Ireland's Ryanair, said first half revenues rose 24 percent to nearly GBP900 million pounds.

It added that it had successfully integrated GB Airways, the domestic rival it bought in October.