PORTLAND, Maine -- Amtrak petitioned a federal panel to allow the Downeaster to travel at 79 mph as the rail authority reported another strong month for ridership and revenues in March, a wire service reports.

The Downeaster had 25,119 riders generating $399,000 in revenues in March, pushing total revenues to $1.33 million since mid-December, said Michael Murray, executive director of the Northern New England Passenger Rail Authority.

Within 3 1/2 months, the Downeaster has already achieved 40 percent of revenue projections for the first year, Murray said.

"Certainly, we are now in a position to generate trends and they're very positive," he said Wednesday. "There is every expectation that we'll meet and exceed the initial ridership projections and associated revenues."

As the rail agency was tallying numbers, Amtrak was back before the U.S. Surface Transportation Board, asking the agency to intervene in a dispute with Guilford Rail Systems over the Downeaster's speed.

The Downeaster has been operating at 60 mph but Amtrak and the rail authority believe it can run safely at 79 mph.

Guilford, which owns 77 miles of track between Portland and Plaistow, N.H., has contended all along that the rail authority should have used heavier rail when overhauling the track.

Amtrak, the rail authority and the Federal Railroad Administration all maintain that passenger trains across the country operate safely on the 115-pound rail used in the track overhaul.

Sandy Mayo, a lawyer for Amtrak in Washington, said independent tests ordered by the Surface Transportation Board demonstrate the Downeaster can operate safely at speeds higher than 60 mph.

"It's (the consultant's) conclusion that the track, with a couple of minor exceptions ... will support 79 mph operation. Guilford takes exception to that and we just think Guilford is wrong," he said.

David Fink, Guilford's executive vice president, did not immediately return a message at his office in Massachusetts.

Mayo expects the board to announce within a week whether it will intervene. If it does, then Guilford will have an opportunity to respond. A decision would not be expected until July at the earliest.

The higher speed would shave 15 minutes off the Portland-to-Boston trip and increase its prospects for success, supporters say.

Even at the slower speed, Murray is pleased with the numbers so far.

March ridership was down by 600 people compared to February, when there was a school vacation week in Maine, but revenues were the highest since the Portland-to-Boston service was launched in mid-December.

So far, 85,249 passengers have ridden the Downeaster, bringing in revenues of $1.33 million, Murray said.

That puts the Downeaster well on its way to meeting the rail authority projections for total ridership of 320,000 and revenues of $3.3 million in the Downeaster's first year of operation.

Murray still plans to meet with the Massachusetts Bay Transit Authority to discuss, among other things, arrival and departure slots at Boston's North Station that are more convenient for Maine riders.

He also wants to discuss three-part tickets allowing riders to take the Downeaster to North Station and the T's Orange Line to South Station to get access to Amtrak's Northeast Corridor.

The Downeaster went into operation on Dec. 15 with four daily trips in each direction between Portland and Boston. Stops include Saco and Wells in Maine; Dover, Durham and Exeter in New Hampshire; and Haverhill in Massachusetts. Seasonal stops in Old Orchard Beach, Maine, begin on June 1.