FILE PHOTO: The Independence of the Seas cruise ship moored at the Grand Port Maritime Marseille (GPMM), in Marseille, France, July 5, 2018. REUTERS/Jean-Paul Pelissier

MARSEILLE, France (Reuters) - The main cruise ship operators in French waters have agreed on measures to limit pollution caused by their vessels, including hooking up to the power grid instead of keeping their engines running during stopovers.

The “Blue Charter” agreement signed in Marseille by Costa Cruises, MSC Cruises, Royal Carribean Cruises and Ponant also pledged to use less-polluting fuel when maneuvering in harbors as well as other measures to reduce emissions.

The four signatories transport 95% of the passengers and account for 85% of the stopovers in Marseille, which is France’s number one cruise ship port and the fourth-biggest in the Mediterranean, with 1.75 million passengers last year and a target of 2 million in 2020.

The move comes ahead of new regulations from the International Maritime Organization (IMO), which will require all ocean-going ships to reduce the sulfur content in fuels used in their vessels from Jan. 1, 2020.

The economic benefits of the cruise industry for Marseille are estimated at about 350 million euros ($389 million) a year and include about 3,000 jobs, but local residents’ associations have long fought pollution from cruise ships.

According to official local data, fumes emitted by cruise ship chimneys are responsible for 40% of the area’s nitrogen oxide emissions, 32% of the sulfur dioxide emissions and 15% of its particulate matter pollution.

Last month Mediterranean resort town Cannes, France’s fourth-biggest cruise ship port, said it would ban the most-polluting cruise ships from next year in an attempt to boost air quality in the city.