WASHINGTON - The world's largest cruise ship company will adopt technology from power plants and automobiles to reduce air pollution from the massive diesel engines powering its ships.

In a tentative agreement reached Thursday with the Environmental Protection Agency, Carnival Corp. will deploy scrubbers to reduce sulfur dioxide and filters to trap soot on as many as 32 ships over the next three years. At port, the ships will either plug into the electrical grid, rather than idle, to reduce pollution or use a lower sulfur fuel.

Emissions from oceangoing vessels had largely been unregulated and contributed to 30 major U.S. ports violating air pollution standards. In 2010, the International Maritime Organization, at the EPA's request, created buffer zones along U.S. coasts requiring foreign-flagged ships to reduce pollution.

The steps Carnival is committing to take will cost the company more than $180 million and apply to ships operated by Carnival Cruise Lines, Holland America Line, Princess Cruises and Cunard. But if the technology does not meet or exceed the standard, as Carnival expects, the company will have to resort to a more expensive solution, lower sulfur fuel.

Scrubbers have been employed on power plants for decades and diesel trucks and cars have long used filters to reduce the soot that comes from exhausts. The challenge with cruise ships was finding the space for such equipment. Anyone that has taken a cruise knows that it's tight quarters.

Royal Caribbean and Norwegian cruise lines have already agreed to reduce emissions. They too will test out different pollution control technologies.