Senate President Therese Murray said the MBTA needs additional revenue to address its projected $161 million budget shortfall, but she indicated she did not favor an increase in the state’s gasoline tax.

Murray said gasoline prices are currently forecast to range between $4 and $5 a gallon this summer and she didn’t want an increase in the gas tax making the price spike worse. She said the MBTA needs either additional state revenues or for other state agencies or authorities to shoulder transportation costs currently paid by the T.

“Everyone knows there’s got to be a fix on the transportation funding,” Murray said after a press conference at the State House.

The T is proposing to raise the price of fares and passes by an  average of 35 to 43 percent and to cut bus routes, eliminate ferry services, and hike discounted fares for students, the elderly, and the disabled. Boston Mayor Thomas Menino, in a letter to Murray and other state leaders on Monday, called for an increase in the gas tax or some other state levy to avoid many of the service cuts. He said he favored “modest fare increases.”

Previously, Murray had said she would wait until MBTA hearings on fare increases and service cutbacks are concluded before voicing her opinion on what should be done. Gov. Deval Patrick, who in his first term proposed a gas tax increase that was rejected by the Legislature, has cited a need for a comprehensive solution to the T’s funding woes but has declined to be specific.

Some analysts are forecasting that gasoline prices could top $4 a gallon this summer, but the most recent estimate by the US Energy Information Administration  says regular-grade gas should average $3.48 a gallon in 2012, 4 cents lower than the 2011 average. During the peak summer driving months, the government said, prices could average about 5 cents a gallon higher.