PORTLAND, Maine — Amtrak’s Downeaster that runs between Portland and Boston bounced back from a dip last summer and fall to finish the fiscal year with its best performance yet, an official said Friday.

Ridership rebounded after losing ground in the first five months of the fiscal year to finish 1 percent ahead of the previous year, said Patricia Quinn, executive director of the Northern New England Passenger Rail Authority. Ticket revenue for the fiscal year that ended last month hit an all-time high as well, at $6.7 million.

Next week, work begins on a long-awaited upgrade of 30 miles of track to bring the train northward to Brunswick. The $35 million project, funded with federal stimulus money, will support 200 jobs.

“To finally have people up there in hard hats and vests and getting paid and making things happen — to me, that’s a big day for us,” Quinn said. “We finally see things starting to pay off.”

Details of the track overhaul that’ll allow the Downeaster to chug from Portland to Brunswick at 70 mph will be released Monday at a news conference in Brunswick. The new service is due to begin in fall of 2012.

Expanding to Brunswick and Freeport has been a goal since the Downeaster began service in December 2001, but it took a federal grant using stimulus money to make the project a reality.

All told, 474,058 passengers rode the train in the past fiscal year; the expansion northward is expected to boost ridership by another 36,000 passengers, Quinn said. The ticket revenue roughly equals taxpayers subisides: $1.3 million provided by the state and $5.3 million from the federal government.

Federal officials rejected a second proposal seeking $52 million for track improvements between Portland and Plaistow, N.H., as part of an effort to further boost the train’s speed and make it possible to increase the number of daily round-trips between Portland and Boston from five to seven.

The rail authority plans to conduct more environmental studies this year before resubmitting the proposal for new sidings and track improvements, Quinn said.

The Downeaster went into operation with service between Portland and Boston’s North Station. Existing stops between Portland and Boston are Old Orchard Beach, Saco and Wells in Maine; Dover, Durham and Exeter in New Hampshire; and Haverhill and Woburn in Massachusetts.