LOS ANGELES (AP) -- Three environmental groups are suing the Federal Maritime Commission over the clean trucks program at the ports of Los Angeles and Long Beach.

The suit filed Monday alleges the agency violated environmental laws when it sought a court order to halt parts of the program that could lead to the replacement of about 18,000 older trucks.

The two ports began the $1.6 million effort last month, hoping to reduce diesel truck emissions by 80 percent within five years.

The Natural Resources Defense Council, Sierra Club and Coalition for Clean Air filed the suit in U.S. District Court, claiming the commission failed to consider public health and environmental damage.

The commission says the new rules will reduce competition and either increase transportation costs or reduce service at the port.