Last year, the Senate Energy and Natural Resources Committee attempted to set ground rules for a 1991 referendum on the political future of Puerto Rico, approving a measure that offered residents of the impoverished island millions of dollars in increased welfare benefits if it became a state.

Yesterday, the Senate Finance Committee decided to strip away many of those benefits.

Finance Chairman Lloyd Bentsen (D-Tex.) said his panel's action was an attempt to "level the playing field" among the three options that would be presented to island residents next summer in a referendum over Puerto Rico's political future. If approved by Congress, the Senate measure would allow voters there to decide whether the island becomes a state, becomes independent, or continues as a U.S. commonwealth.

Advocates of independence and commonwealth status expressed delight with the committee action, which reverses the financial incentives approved last year. The Senate Energy and Natural Resources Committee proposal would have boosted a wide range of welfare payments, but statehood opponents charged that it was an attempt to "bribe people into statehood."

Yesterday, after the Finance Committee voice vote, Gov. Rafael Hernandez Colon, who had leveled those charges, expressed satisfaction that the referendum would not be tainted by financial considerations.

Statehood party leader and former governor Carlos Romero Barcelo, however, was furious. He denounced the Finance Committee vote as "unacceptable" and said his forces will press for passage of a House measure that takes a sharply different approach to resolving Puerto Rico's future.

The House bill, expected to be voted out of the subcommittee on insular and international affairs this afternoon, would authorize the referendum, but would require Congress to pass additional legislation spelling out any financial implications.

Whatever course Congress chooses, island leaders agreed yesterday that Congress must act swiftly if the referendum is to be held next summer. "It's going to be tight, it's going to be very tight," said Hernandez Colon, a commonwealth advocate.

An effort by Sen. Daniel Patrick Moynihan (D-N.Y.) to advance the proposed date of Puerto Rican statehood to 1993 from 1996 produced sharp divisions within the committee and confronted united Republican opposition. "I knew I would be in trouble when the administration supported me," Moynihan joked after his proposal failed on a 14 to 6 vote. Despite White House advocacy of a 1992 admission date, not a single GOP senator supported Moynihan.