The Seattle Monorail Project announced today that it has reached a tentative agreement to open the 14-mile Green Line by December 2010.

For nine months, the agency and lead contractor Fluor Enterprises have negotiated what now appears to be a $1.6 billion contract to build the tracks and furnish the trains. Overall project costs will be higher because of real estate and planning costs. Also, subsidies are needed to operate the system.

Two of the 19 stations have been either cut or delayed — at 35th Avenue Southwest and Avalon Way in West Seattle, and at the corner of Elliott Avenue and Mercer Street in lower Queen Anne. A financial-district station at Second Avenue and Madison Street is funded, but the land may not be available on time, officials said.

The agency would not release documents nor any pictures of the proposed system. Officials said they plan to start publishing the details on June 20, after lawyers double-check the information.

Some aesthetic features are subject to further negotiations and city design reviews.

Before groundbreaking, the city must complete a financial review to ensure the line is affordable, and then the Seattle Monorail Project must woo investors.

Joel Horn, the monorail's executive director, said reserves and contingency funds would be "well north of $200 million," something he said ought to help reassure the city.

The plan still includes tall columns in downtown Seattle, nicknamed "irises," which will place tracks at two different levels - so passengers can board from different floors of a narrow station.

"I really feel like this is the biggest day for the monorail so far. It isn't just the agency or activists saying the project can be done. This is a major corporation putting their balance sheet on the line," said monorail board member Cleve Stockmeyer. "It's can-do day. We can do it."

Mayor Greg Nickels issued a statement congratulating the agency for moving closer to what he called a 21st-century transportation system.

Opponents are expected to mount a final lobbying effort, asking the City Council to halt the project.

Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com