Construction is to begin this week on a long-delayed $80 million conference center at Rockville Pike and Marinelli Road, causing major changes in commuter parking patterns at White Flint Metro station.

Starting Saturday, the 990-space parking lot on the west side of Marinelli Road and Rockville Pike will be closed. The lot, directly across from the Metro station, will be the site of the new conference center.

Commuters can park at two other lots and on nearby streets, according to Montgomery County officials. One lot, the White Flint East Metro parking lot, is at the east side of Rockville Pike and Marinelli Road. Another is a county-owned commuter lot at Montrose and Randolph roads.

There are 449 metered, 12-hour parking spaces on Marinelli Road and Nebel Street, just east of Rockville Pike; on Executive Boulevard at Nicholson Lane; on Nicholson Court and Woodglen Road, both just off Nicholson Lane; on Old Georgetown Road at Montrose Road; and Old Georgetown Road at Route 355. In addition, three bus routes will be rerouted to provide better service to the White Flint Metro station.

Construction of the new conference center, which will include a 120-seat amphitheater, a grand ballroom, restaurant, lounge and outdoor cafe, will last 20 months.

County officials said they believe that enough spaces exist near White Flint Metro to accommodate displaced commuters. They said that once an additional parking garage opens in March at Shady Grove Metro, more commuters will start using that area to park instead of coming to White Flint.

"People are going to have to get used to parking somewhere else," said Tina Benjamin, manager of public-private partnerships at the Montgomery County Department of Economic Development. "But there's adequate parking in the North Bethesda area."

The conference center, to be known as the White Flint Conference Center, will be adjacent to a 225-room Marriott hotel. It is expected to open in late 2004.

Tourism and county officials say the center will be an economic boon to the county, attracting "out-of-town business," government workers and associations requiring large spaces outside of the city to meet. Meeting planners have been turned away on holding functions in the county because only a few hotels and country clubs can accommodate large groups.

"There have been things we haven't been able to book because we don't have the space," said Kelly Groff, director of the Conference and Visitors Bureau of Montgomery County. "We're really pleased to see the project moving along."

The state has put $20 million into the project, the county paid $20 million for the land and private developers, and investors are adding $40 million.

According to studies in 2000 by Basile Baumann Prost & Associates of Annapolis, the convention center is expected to bring an estimated $2.4 million a year in direct and indirect revenue from spinoff spending in restaurants, hotels and stores to state coffers. For Montgomery County, the center will bring in about $800,000 in direct and indirect spending annually.

But some meeting planners caution that large corporations and associations are not sending as many attendees to meetings because of the slowed economy, leaving some conference centers empty across the country. Montgomery officials are optimistic that when the economy improves, their center will be in demand.

"Although the economy is still slow at this point, with the timeline on the construction of this project, we think it will open when things are much better," Groff said. "We're assuming the economy will be better and the demand for our destination will be there when it opens."

Construction of the center has been delayed for years because of complaints from nearby residents who said it would cause too much traffic and noise in the area.

The center was proposed in 1995 by Montgomery County Executive Douglas M. Duncan (D) and was to open in 1998. At that time, its estimated cost was $60 million. Because of inflation and a hot construction market, the price has risen to almost $80 million, officials said.

Much of the delay was due to the efforts of David H. Brown, who lives in a condominium near the center. He became very involved in 1997 in fighting the center and filed administrative appeals with the county planning board.

Ultimately, his case went to the Maryland Court of Special Appeals, which declined to hear it, citing insufficient evidence that the project would cause too much noise and traffic. The county could have gone ahead with the project but didn't want to risk having to tear it down if Brown won.

Brown, who now spends much of his time in the winter in Delray Beach, Fla., did not return phone messages left at his North Bethesda condo.

An artist's rendering of the planned conference center and hotel near the White Flint Metro station, expected to open in late 2004. The center will have 36,000 square feet of space; the Marriott hotel will have 225 rooms.