A legal wrangle has broken out between the two largest ski schools on the French slopes over accusations of unfair competition.

Now in its 70th year, the ESF (Ecole du Ski Français) is the largest ski school in the world, with over 15,000 instructors spread over 250 ski resorts in France.

Established since 1974, the ESI (Ecole de Ski Internationale) has sought to break the dominance of the ESF, and now has 1700 instructors on 77 French ski slopes.

Whilst the instructors of the ESF use distinctive red ski suits with a high level of visibility in the resorts, the black, white and yellow tunics of the ESI are less familiar.

In spite of the best efforts of ESI to establish a stronger presence, it is the brochures and buildings of the ESF that are omnipresent in the ski stations, with the ESI often relegated to an office in the local village.

Despite these difficulties, ESI has established a good reputation amongst many users for the quality of its instructors, snowboard classes and for limiting class sizes to a maximum of 12 persons.

The ESI considers that the trademark name of the ESF, together with the red, white and blue tunics of its instructors unfairly gives the impression that the company is an official public body.

This is not the first time the two companies have been involved in a legal dispute. In 1991 ESI won a battle to be granted free, priority access to the ski lifts, in the same way that the ESF already benefited from this concession.