Analysts have clipped expectations for budget carrier Easyjet, after the firm admitted encountering limited turbulence stemming from the 11 September attacks.

The carrier, which has touted its immunity from the worst effects of the terror strikes, warned that insurance policy premiums had "increased substantially".

Easyjet also said it was reassessing the book value of its holding in the Airline Group, the firm which has taken over the running of Britain's air traffic control business, Nats.

Nats has reportedly received an emergency �60m in funding - half of it from the UK government - to address revenue shortfalls stemming from the aviation crisis.

Analysts at investment bank UBS Warburg on Tuesday trimmed their rating of Easyjet shares.

But the bank still rated Easyjet stock a "buy", and the carrier said that, despite the extra insurance costs, it was - unusually - placed to report a profit for the October to March period.

Beating the trend

The firm has benefited through reduced fuel prices, and a continuing rise in customer numbers.

"Easyjet has experienced strong passenger demand for travel," the airline said on Tuesday.

The surge has helped Easyjet offset lower ticket yields in an increasingly competitive aviation market, the briefing added.

Overall, Easyjet had turned in a "robust performance" over the October to March period, which would see the company return a profit when a full earnings statement is made next month.

Typically, Easyjet has run at a loss over the winter period, with profits boosted by the summer holiday season.

"Favourable" weather, and the falling of Easter in March, had contributed to the improved figures, Tuesday's briefing said.

Easyjet shares stood 13p lower at 498p in afternoon trade.