In the battle for the presidency of the Maryland Senate, a big loser appears to be Montgomery County, whose senators tried to be big-league political power brokers but more likely will end up stripped of their only major committee chairmanship and facing the prospect of four years in isolation.

"It shows what happens when you try to be honorable," said Montgomery's Sen. Laurence Levitan, who now seems destined to lose his chairmanship of the powerful Senate Budget and Taxation Committee.

Unlike Prince George's County senators, who likely will gain at least two leadership positions as a result of the maneuvering, Montgomery senators waited too long to endorse the Baltimore senator who is likely to win the senate presidency race.

One of the long-range casualties of this preelection skirmishing also could be the traditional Baltimore-Montgomery voting coalition, one of the oldest and most successful alliances of post-World War II legislatures. It was a partnership that produced a raft of liberal legislation for Maryland and favorable state revenue distributions for Montgomery.

County senators, faced with the likelihood that Levitan will be replaced as chairman of the budget committee, are threatening to join rural senators to form an anti-Baltimore voting bloc for the next four years.

Sen. Melvin A. (Mickey) Steinberg, a wise-cracking Baltimore County labor lawyer, now appears to have gathered enough votes to beat Senate President James Clark of Howard County for control of the 47-member state Senate. The presidency will be decided when the Democratic caucus votes in December, after the Nov. 2 election. Democrats hold an overwhelming majority in the Senate.

In his bid for the presidency, Steinberg put together an early coalition of Prince George's and Baltimore County senators. Prince George's County emerged a big winner. Steinberg won early backing from Prince George's senators who had battled bitterly with Clark this year over legislative redistricting.

If Steinberg becomes president, Sen. Thomas V. Mike Miller, chairman of the county Senate delegation, has been promised the posts of majority leader and chairman of the Judicial Proceedings Committee. Also, Prince George's Sen. Tommie Broadwater Jr. has been assured the chairmanship of a budget subcommittee dealing with law enforcement and transportation, which is now chaired by retiring Montgomery Sen. Victor L. Crawford.

Steinberg had wanted to add Montgomery to his coalition to give him the votes needed to topple Clark. But when Montgomery senators dragged their feet, Steinberg went vote-hunting among Baltimore city senators. Steinberg said he promised the Budget and Taxation Committee chairmanship to Baltimore Sen. Clarence Blount in return for support from Baltimore city. The city's senators voted 6 to 3 to back Steinberg over Clark.

"My commitment to him Blount is concrete," Steinberg said.

Montgomery was similarly locked out of the leadership for the four years starting in 1974, when they backed the loser, Clark, instead of winner Steny Hoyer from Prince George's County in a hard-fought race for the Senate presidency. Steinberg said Montgomery need not worry if he is elected president, since he said he will always listen to its residents' concerns.

Montgomery considered Levitan's chairmanship crucial to the county, especially since the 1984 General Assembly is scheduled to reexamine several key state-aid formulas used to distribute everything from education funds to money for local police departments to highway repair dollars.

Montgomery senators were the ones who fought to get all those various aid formulas reopened, back when they were quarreling with Baltimore early this year and when they thought Levitan would be controlling that key fiscal committee.

Levitan also has touted his chairmanship as his major selling point in his reelection campaign. His brochures call him "One of Montgomery County's most effective legislators," and one primary election leaflet said Levitan "has the experience and the position to brace the state against federal budget cuts and the county against attacks by others to reduce funding allotments."

Levitan's opponent, state GOP chairman Allan C. Levey, has already started telling audiences that there is no reason to send Levitan back to Annapolis.

Montgomery senators said they were slow to take sides in the Clark-Steinberg battle partly out of loyalty to Clark, whose district includes part of Montgomery and who sits in on Montgomery delegation meetings. Also, Levitan said, Montgomery was hoping to form a coalition with Baltimore city to get even more leadership positions out of the next Senate president.

Levitan and Montgomery Sen. Sidney Kramer said they believed they had a commitment from Baltimore to stay neutral until after the November election. But while they had commitments from only three Baltimore senators, Steinberg was busy wooing six others to his side.

Steinberg approached the Baltimore senators one by one with a grab bag of committee chairmanship promises and preprimary endorsements. Steinberg was helped in his wooing of the city senators since he had endorsed two challengers who beat incumbents in two Baltimore districts. He also received some lobbying help from Baltimore Mayor William Donald Schaefer, from former Gov. Marvin Mandel, and from his former fund-raiser Irvin Kovens.

Steinberg said he approached Levitan three times seeking support, but he and other Montgomery senators insisted on waiting. "It backfired on them," he said. "They took a gamble and they lost. They bet on the wrong horses."

The scenario, as it unfolded over the last week, left Montgomery senators accusing Baltimore of reneging on a deal. Said Kramer, "Perhaps we were naive."

Levitan and Kramer said they still are optimistic about finding some sort of last-minute arrangement, such as persuading Blount to remain as vice chairman. But Steinberg at this point doesn't need Montgomery's votes to win the presidency, and the senators are resigned to making threats about sabotaging Baltimore-backed initiatives for the next four years, and making life generally unpleasant for Steinberg unless he gives Montgomery a chairmanship.

Steinberg dismissed the threats as posturing.

"We could make a sizable bloc that could impede the flow of legislation for the next four years," Kramer said. "Montgomery County would reciprocate in kind if [we] were not part of the leadership."