The main pilots' union and Air France's (AIRF.PA) top unions asked all staff on Friday to stage a walkout from February 6-9.

Air France said on its website it would be forced to reduce its flights if the strike took place and did not exclude further last-minute cancellations and delays.

France's lower house of parliament, the National Assembly, approved a bill in January to force workers in the air transport sector to give 48 hours notice of any industrial action.

The bill, put forward by President Nicolas Sarkozy's UMP party, was designed to give air operators enough time to prepare for strikes and set up a skeleton service for customers.

Unions have criticised the bill, saying it undermines the rights of their workers.

"This action is renewable," Philippe Vivier, vice-president at pilots' union SNPL told Reuters. "We will have more strikes in February at a date still to be decided."

The union had asked for amendments to the bill, but the transport ministry rejected the suggestions.

France's government had to deploy police at airports before Christmas when private security staff held a last minute strike, a move that threatened to paralyse flights during the busy period.

The new bill is similar to a rail and urban transport law introduced in 2007 which ensures a minimum service guarantee.

(Reporting By Gerard Bon and John Irish; Editing by Andrew Heavens)

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