PARIS — France has agreed to sell Russia an advanced amphibious warship and is considering a Russian request for three more, French defense officials said Monday. It would be the first major arms deal between Russia and a NATO member.

French President Nicolas Sarkozy approved the sale of one Mistral assault ship after months of discussions, but then Russian naval officials submitted a request for three more, said Jacques de Lajugie, head of international development at the French arms agency DGA.