Gov. Harry Hughes will ask the General Assembly this week to increase the gasoline tax for trucks by 2 cents a gallon and to raise truck registration fees by 5 percent.

The proposals were sideswiped immediately by the truck industry. "We are unalterably opposed to any additional tax levied on the trucking industry," said Walter C. Thompson, executive director of the Maryland Motor Truck Association.

In addition, several key legislators balked at the proposed increase in registration fees, saying that trucks registered in other states would pay less, while causing just as much damage to Maryland roads.

Wayne A. McDaniel, Hughes' executive assistant in charge of transportation issues, said today that the truck tax and higher registration fees would raise $14.5 million in new revenues for the ailing transportation trust fund, which is used to repair the state's roads and bridges.

The tax and fee plan for trucks is part of Hughes' transportation package that includes a 4 percent across-the-board increase in the price of a gallon of gasoline at the pump. Trucks weighing more than 10,000 pounds would have to pay the 2-cents-a-gallon truck gasoline tax in addition to the 4 percent fuel tax increase.

"Our current project schedule is based on getting both taxes through this year," McDaniel said. "There's truth to the rumor that our roads and bridges need repair."

Hughes had announced plans late last year to increase the truck tax, pending the results of a study in which the tax rates were based on the amount of road damage caused.

That University of Maryland study first concluded that trucks already pay more than their fair share. It was a politically embarrassing conclusion for the governor and served as fuel for opponents of truck taxes. But the researchers, on orders from Hughes, reworked their calculations and came back with another conclusion: that trucks here were undertaxed by as much as $30 million.

Thompson, of the truck lobby, charged: "That was nothing more than a game of checkers, moving the numbers around."

Thompson said the increased registration fee "is going to drive business right out of this state."

But Sen. Laurence Levitan (D-Montgomery), chairman of the Senate budget and tax committee, which will consider the tax, said that Maryland's truck registration is one of the lowest of area states.