EasyJet (EZJ.L), which has increased the number of flights between top business destinations, said on Wednesday nearly half its summer seats had been sold.

Chief executive Carolyn McCall said that would help boost revenues per seat by "the low to mid single-digit range".

The Luton, southern England-based airline posted a pretax loss of 112 million pounds for the six months to March, compared with its guidance for a loss of 110-120 million and a 153 million loss in the 2010/11 period.

Its first-half revenue rose 16 percent to 1.465 billion pounds, while the number of passengers carried grew 5.4 percent to 25.2 million, as it continued to grow its share of the shorthaul business travel market.

EasyJet, and other groups in the travel industry, often make a loss in that part of their financial year which does not include the summer period.

It said the first-half loss had been cut because it targeted business travellers, raised fares, had tight cost controls, and enjoyed low levels of disruption compared with previous years, and came despite an 87 million pound increase in fuel costs.

"The smaller loss comes against a backdrop of significantly higher fuel costs ... but the performance was led by the top line, with revenue per seat up 12 percent," Espirito Santo analyst Gerald Khoo said.

McCall said: "Average fares have gone up across the industry due to tighter capacity discipline and fuel costs, which were up 22 percent in the (first) half. The oil price is a key challenge and we expect it to stay high.

"The average fare was around 12 percent higher across the network but we do not expect it to rise in the second half."

European airlines have struggled to overcome a toxic mix of high oil prices and sluggish demand in recent months, with low-cost airlines expected to pick up more business as struggling European consumers trade down.

EasyJet has increased frequencies between top destinations in a bid to take a bigger share of the business travel market.

European carriers Air France-KLM (AIRF.PA) and Lufthansa (LHAG.DE) last week reported results battered by higher fuel costs.

Since the start of the year, some 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, the largest airline at London's Gatwick airport, said it had bought 77 percent of its required fuel for the second half.

Its shares, which have risen almost a third in value this year, were up 0.6 percent at 512 pence by 1020 GMT, valuing the company at around 2.0 billion pounds.

(Editing by Dan Lalor)

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