Webjet is ''cautiously optimistic'' about signs of a recovery in travel after posting a 40 per cent lift in net profit to $5.2 million for the first half.

The online booking service said the combination of a rise in air fares, plans by airlines such as Qantas and Jetstar to increase flights, and a strong Australian dollar encouraging people to travel overseas, suggested ''there is the beginning of a demand recovery both internationally and domestically''.

But Webjet has refrained from declaring that a recovery is in full swing, instead saying that is it cautiously optimistic about trading in the second half.

The company would not give formal guidance yesterday but did say it would be disappointed if its second-half profit was not similar to that achieved in the first six months.

Webjet reported a 37 per cent rise to $248 million in the value of ticket sales for the six months to December 31. Earnings per share rose from 4.94c to 6.9c.

The online operator increased its interim dividend to 5c, from 3c in the same half last financial year.

Shares in Webjet rose 1c to $2.30 yesterday, 4c off an all-time high reached last Friday.

The company trumpeted the first-half profit as evidence of its business strengthening despite the environment for the travel industry and the wider economy remaining ''uncertain''.

But elsewhere, the hard-hit travel sector is emerging from a year of pain in which profits were savaged.

Last week Flight Centre lifted its earnings forecasts for this financial year by as much as 33 per cent after stronger-than-expected ticket sales in the first half. Qantas has said an improvement in average air fares and demand was set to steer it back into profitability in the first half.

Despite Webjet's bullish result, some analysts remain cautious about its online model because its competitors do not charge booking fees. Webjet gains about two-thirds of its revenue from booking fees.