PORTLAND – Maine’s lakes, rivers and coastal waters will receive less pollution in the next few years if the outboard motor industry lives up to the terms of a voluntary agreement signed Monday.

The deal with state and federal regulators calls for retailers and manufacturers to phase in cleaner, quieter engines before federal rules require them in 2006.

Industry officials in Maine agreed that 75 percent of their outboard sales would be clean engines this year, to be followed by 80 percent next year and 95 percent in 2004. They signed a nonbinding memorandum of understanding with the Environmental Protection Agency and state Department of Environmental Protection.

Federal regulations will require all new outboard motors to be low polluting four years from now.

Data on the percentage of low-emissions outboard motors now sold in Maine are not available, said Kevin Zinn of the National Marine Manufacturers Association.

But the agreement will dramatically reduce air and water emissions from outboard motors, said Bob Varney, New England administrator of the EPA.

The EPA estimates that the low-pollution engines burn 35 percent to 50 percent less gas than older motors and reduce emissions by at least 75 percent.

The engines also start up more quickly and make less noise, features that have spread their appeal among consumers in Maine, according to industry representatives.

Four-stroke and two-stroke direct fuel injection engines typically cost about 15 percent more than high-emissions engines, but prices are expected to drop as production and demand increases, Varney said.

Varney, formerly the top environmental official in New Hampshire, has been an advocate for the voluntary phase-in of low-emissions motors. He is signing deals similar to Maine’s in each New England state.

Other states have taken tougher approaches. California last year adopted rules that are stricter than federal regulations after an analysis showed a personal watercraft operated for seven hours produces more smog-forming emissions than a 1998 passenger car driven for 100,000 miles.