The Washington Suburban Sanitary Commission has been unable to select a new general manager to run the giant water and sewer agency that serves Washington's largest Maryland suburbs, leaving it without a steward as it prepares to debate whether to become a private company.

The commission, composed of three members each from Montgomery and Prince George's counties, has split evenly on six candidates for the job, including former District Department of Housing and Community Development director Richard Montielh. The private votes, according to one commissioner, have been cast almost entirely along county lines over the course of several months.

Some WSSC commissioners and others outside the agency believe a national search begun in November may need to be restarted to find a candidate both counties endorse. The search produced a list of 13 candidates earlier this year that commissioners have whittled without agreeing on anyone, although they may still choose an internal candidate rather than start from scratch.

"At this point, we're not interviewing," said commission Chairman W. Gregory Wims, who is from Montgomery. "We're discussing all the candidates that have applied."

At the heart of the deadlock is the longtime tension between the three commissioners from each county--as well as the respective county executives who appoint them--for control of a water and sewer agency with 1.6 million customers. For years, the counties have squared off over construction schedules, contracts and general policy, sometimes at the behest of the county executives.

This appointment, however, comes at a particularly delicate time. A report detailing the merits of transforming the agency, now carrying $1 billion in bond debt, into a private company is scheduled for release in September. With Montgomery officials more willing to consider privatization than their counterparts in Prince George's, each side could benefit from an ally overseeing the agency's daily operation, which would include preparing material commissioners need in making the decision.

"This is a historic thing, with the counties basically disagreeing on control," said Lewis M. Helm, a former WSSC commissioner from Montgomery. "Until you get it resolved you won't get a general manager."

Indeed, the search has taken far longer than commissioners predicted last fall when Cortez A. White, a Montgomery resident, announced his plan to retire June 30 after six years in the job. In a statement to the commission, White said Prince George's officials planned to block renewing his contract, which paid him $128,960 a year. His tenure is shaping the process to pick his successor.

"We don't want another Cortez White," said Del. Rushern L. Baker III (D-Prince George's). "We want someone who will come in there and treat both counties equally."

WSSC commissioners had planned to have the job filled upon White's departure, and state legislators who have taken an interest in WSSC operations say it should have been.

"At some point, the stalemate has to be broken," said Del. Dereck Davis (D-Prince George's), noting that the appointment was more urgent "with privatization looming."

One finalist was Montielh, who left his District job last month with a reputation as an aggressive advocate for economic development in poor neighborhoods. He failed to find a foothold in the new administration of D.C. Mayor Anthony A. Williams (D).

WSSC and Montgomery sources said Montielh was rejected by Montgomery commissioners despite a strong endorsement from Prince George's County Executive Wayne K. Curry (D). D.C. financial control board Chairman Alice M. Rivlin even wrote Montgomery County Executive Douglas M. Duncan (D) urging him to support Montielh. But commission sources said his lack of experience running a water and sewer agency doomed his chances.

"From the Montgomery point of view, we are looking for someone with water and waste water management experience who is competent and who can keep the high quality of service at a reasonable cost. Nothing less," said Kevin P. Maloney, a Montgomery commissioner who declined to discuss Montielh's candidacy.

Curry, of Prince George's, said he met with four of the six finalists and found all to be acceptable for the job.

"It comes down to an inability of the two jurisdictions to get together on any of the the candidates," Curry said. "They just can't agree."

CAPTION: Del. Rushern L. Baker III says he wants a Washington Suburban Sanitary Commission general manager who is fair to both counties.