A slightly trimmed and slightly toned down ethics bill took its first legislative leap yesterday when a state Senate Committee approved it and set the stage for a battle over the need to tighten ethical standards for public officials in Maryland.

After weeks of hearings and work sessions, the Senate Constitutional and Public Law Committee removed a few controversial sections from a far-reaching bill sponsored by Senate leaders and sent it to the floor where debate will begin next week.

"I think it's very strong bill," said Lee D. Perlman, a lobbyist for Common Cause. "If this wasn't an election year and a year in which we had political scandals, we would never have expected to get such a strong bill through this far."

While traditionally cool to ethics measures, Maryland legislators are expected to be more receptive this session because of the coming statewide elections and last summer's political corruption conviction of suspended governor Marvin Mandel.

The issue has already become the source of political rivalry this session because of competing bills sponsored by acting Gov. Blair Lee III and Senate President Steny H. Hoyer, who are running against each other for governor.

As expected, the Senate Committee approved the Hoyer bill yesterday, but only after grafting onto it a few sections of the Lee measure, including a provision to require local officials to pass ethics laws governing their own conduct.

The Lee package included several far-reaching measures that wound up on the committee's cutting room floor, notably a $25 limit on the amount of free food and drink a legislator can accept from any donor in a year. There is no ceiling today.

Another key provision in the Lee measure that would have forced legislative lobbyists to list every dollar spent entertaining lawmakers was stricken because the committee did not want to tamper with the state's year-old lobbying disclosure law.

Lee acknowledged more than a week ago that the bill sponsored by his political rival, Hoyer, would probably prevail but said he felt no particular pride of authorship. "I want a good bill," he said, "I don't care whose name goes on it."

The most controversial portion of the Hoyer bill deleted by the committee was a requirement for lawmakers to disclose the source of their income, a requirement extending to clients of lawyers, accountants, and other professional people.

The committee-approved bill would firm up conflict-of-interest laws and broaden financial disclosure requirements for legislators. The bill also would prohibit lawmakers from accepting gifts from persons whose interests are affected by legislation.

The bill would set up a board to investigate conflicts of interest by public officials. It would have the power to subpoena documents, compel testimony under grants of immunity and order a halt to illegal or improper behavior.

Current ethics laws in Maryland are regarded as weak and largely unenforceable, in part because they represent a hodge-podge of laws enacted separately over the years without much effort to ensure compliance with them.

The measure is expected to get through the Senate with little difficulty because of the endorsement by Senate leaders. The committee member who voiced the lone dissent was Sen. John A. Cade (R-Anne Aeundel), who said, "I think the bill goes way beyond what we should be doing. I resent the fact the committee has been saddled with this in an election-year sweepstakes."