BNP Paribas, Calyon and Sociéte Générale have been hired to work on the €2.8bn ($3.34bn) tie-up between defence electronics group Thales and DCN, the French state-owned warship maker, which was officially launched yesterday by the government.

Sources familiar with the situation said BNP Paribas is acting as adviser to Thales, while Calyon, the investment banking arm of Crédit Agricole is advising the French state, and Société Générale is advising DCN.