Montgomery County Executive Douglas M. Duncan is floating plans for a new way to link Bethesda and Silver Spring by rail, a move he hopes will resolve the 15-year dispute over the Purple Line.

Duncan (D) confirmed yesterday that his staff has started briefing members of the Montgomery County Council on a "compromise route," which he said was devised by Metro officials at his request.

"What I'd like to see is all of us united behind one alignment," Duncan said. "To me, this looks like a promising way to do that."

Duncan has spent his eight-year tenure pushing for a train to carry commuters across the county. Most council members strongly support linking Bethesda and Silver Spring with a double-tracked trolley line. But Duncan has objected to the route, which sends the trains along hiker-biker trails, across the fairways of Columbia Country Club and behind pricey homes in Chevy Chase.

Instead, Duncan has long favored running a heavy-rail line outside the Capital Beltway, bypassing Bethesda and Silver Spring to serve such communities as White Oak, Wheaton and Grosvenor. The plan would cost considerably more but take more vehicles off the county's clogged roads, planners say.

The compromise involves using Metro trains to carry riders from the Medical Center station near the National Institutes of Health, alongside the Beltway and then south into the Silver Spring station.

Duncan's new quest for consensus is driven by concern that any hope of federal funding for a cross-county rail project is slipping away while the county fights over competing plans.

Congress is to reauthorize the nation's transportation funding this year, which means that most states are readying proposals and will start jockeying for federal dollars as early as March. If Maryland does not submit a Purple Line proposal for funding on Capitol Hill this year, it will be at least five years before the next opportunity arises.

"If we're united, our request for federal funding becomes that much stronger," Duncan said. Like Duncan, Gov.-elect Robert L. Ehrlich Jr. (R) has opposed the inside-the-Beltway trolley.

Although Duncan played a pivotal role in helping several council members get elected in November, and emerged with a hefty store of goodwill, it appears that the effort has not translated into clout on this issue.

Even some of Duncan's closest allies on the council reacted tepidly to the compromise plan. Council member Steven A. Silverman (D-At Large) called it "intriguing" but added: "There are lots of questions that would need to be answered. If there's a compromise that can be reached that's cost-effective, and that can get the support of both the county executive and the governor, I'm willing to look at it."

Other members were even less enthusiastic. Council member Tom Perez (D-Silver Spring) called it dead on arrival.

He said Duncan's staff estimated the cost of the compromise route at $600 million, compared with the roughly $400 million price tag for the trolley plan.

"I can't justify telling my constituents that we need to spend $200 million more in these fiscally challenging times," he said.

Council member George Leventhal (D-At Large) said he believes Duncan's latest move is a signal that he may be starting to relent.

"Doug is moving a little close to what makes the most sense," he said. "I welcome his movement, and I hope he gets on board with an 'Inner' Purple Line."

Longtime activists on both sides of the Purple Line fight were reluctant to comment on Duncan's compromise plan because none had seen it. But some said they have serious doubts about the proposal.

"One thing is very clear," said Ben Ross, president of the Action Committee for Transit. "He's willing to put the Purple Line anywhere at all, as long as his contributors from the [Columbia] Country Club don't have to look at it while they play golf."

Duncan dismissed such criticism, saying his goal has been clear for years: to give local residents means to travel across the county and to Virginia by rail without damaging hiker-biker trails.

"This met that goal," he said. "But now, I want to hear what others have to say."

While some council members were quick to dismiss the compromise route, the council as a whole may not rule it out entirely. One source close to the council said members probably will send the proposed route to Montgomery County's representatives on the Maryland-National Capital Park and Planning Commission for a quick review before passing judgment.

Because the planning commission members have strongly backed the Inner Purple Line trolley proposal, a blessing from them could breathe real life into the compromise plan.

"If they say no," the council source said, "this idea won't go anywhere."