PORTLAND (AP) – Soaring gas prices played a role in a 28 percent gain in ridership for Amtrak’s Downeaster during the latest fiscal year, officials said Monday.

The ridership gain was the biggest of any Amtrak train in the period ending June 30, and revenue for the month of June set an all-time record of more than $590,000, said Patricia Quinn, executive director of the Northern New England Passenger Rail Authority.

Gas prices were a primary reason for the increase in passengers, along with a fifth daily run and added capacity on the trains, she added.

The rapid growth has the Portland-based rail authority considering all options, including negotiating with rail owner Pan Am Railways to add a sixth daily round trip.

“What’s going to happen is we’re going to get maxed out,” Quinn said. The early train out of Portland each morning already is running at 90 percent of capacity, and the 5 p.m. train out of Boston is typically 95 percent full, she added.

The passenger rail authority board will meet later this summer to consider options for expanding capacity, as well as for expanding the service northward to Brunswick.

Gov. John Baldacci has committed to include funding for the Downeaster in his state budget next year to make up for the loss of a $6 million federal grant that’s due to expire, said Mark Latti, spokesman for the Maine Department of Transportation.