A filibuster that brought the Maryland Senate to a standstill for 23 hours ended early today after organizers of the parliamentary deadlock won a key concession from their opponents and preserved contested elections for the state's 104 circuit court judges.

"The compromise clearly tilted our way," said Howard A. Denis (R-Montgomery), one of several conservative white senators who joined with liberal blacks in the filibuster. They were seeking to alter a bill that would have abolished the current practice of allowing challengers to run against circuit court judges in the first scheduled election after their appointment to the bench.

Led by Sen. Clarence M. Mitchell III (D-Baltimore), the filibuster organizers ended their nonstop speechmaking at 3:15 a.m. today after forcing the Senate leadership to amend the legislation and require contested elections four years after a judge's appointment by the governor.

The legislation would require judges to run for election in nonpartisan general contests, rather than in party primaries and in general elections as they do now.

After being elected, judges would serve for 10 years before facing reelection, when they would run only against their records not other candidates, according to the bill. Election of district court judges, also included in the original bill, was dropped as part of the compromise.

A related bill establishing a Judicial Nominating Commission was held for more amendments today. That legislation would codify nominating commissions now established by the governor and give the Senate greater power over commission membership.

Several senators credited President Melvin A. Steinberg (D-Baltimore County) with negotiating the anticlimactic end to the filibuster that threatened to tie up the Senate through the weekend.

The turning point came at about 1:30 a.m. when Steinberg called Denis and several black senators, including Mitchell and Decatur W. Trotter (D-Prince George's), into his plush office near the Senate chamber and suggested a compromise that included contested judicial elections, according to participants.

Sen. Thomas V. Mike Miller (D-Prince George's), a committee chairman and Steinberg's deputy majority leader, later argued vehemently against the concession, he said.

"The unsettling thing is that contested elections -- the beauty contests, the popularity contests -- are still in the legislation," Miller said. "I am not happy with this compromise." He added that he reluctantly agreed to the compromise so the Senate could resume the schedule of hearings and voting sessions disrupted by the filibuster.

Miller and others contend that judges should be free from turmoil of local politics, including raising funds from those who may practice law before them. Mitchell and his allies argued that such views are elitist and that contested elections open Maryland's judiciary to minorities and other groups once denied seats on the circuit bench.

Even though the full Senate is expected to approve the bill by Wednesday, its most ardent supporters conceded today it could die in the House, where last year a committee killed a somewhat different proposal.

Del. Joseph E. Owens (D-Montgomery), the powerful chairman of the House Judiciary Committee and a supporter of circuit court elections, said the compromise "doesn't make sense." Lengthening from one to four the number of years a judge serves before election is "very unfair" to those who lose and must return to private law practice, Owens said.

John P. Corderman, a Washington County circuit court judge and head of the 10,000-member state bar association, said it was "unfortunate" that the bill still allows contested elections but praised the provision allowing judges to run on four-year records.