Constellation Brands is closing its Blackstone Winery tasting room and winemaking facilities in Kenwood this March and will put the property up for sale.

Constellation, the world's largest wine company, moved the production of its Blackstone Sonoma Reserve wines last summer to the Ravenswood Winery outside Sonoma. The Kenwood tasting room on Sonoma Highway remains open, but the winery was last used in 2009.

Six of the Kenwood facility's 10 employees are moving to other Constellation wineries in Sonoma County. The company will seek positions for the remaining four employees before the Blackstone winery closes, a spokeswoman said Wednesday.

"It's not taking place until March 1 so we've got some time," said Nora Feeley, Constellation's vice president of communications in San Francisco.

The switch in production facilities will allow "significant savings," Feeley said. The wine will continue to be made in the county without compromising quality, she said.

The price has not yet been set for the Kenwood facilities, she said. The site includes a guest house and a vineyard of slightly more than two acres.

The Blackstone brand was purchased in 2001 when a partnership of Constellation and BRL Hardy teamed up to buy the Codera Wine Group for $140 million. Codera began in 1990 as a "virtual winery," without vineyards or production facilities. It soon found success selling merlot, a red wine that 15 years ago began to rival cabernet sauvignon in popularity.

Constellation later acquired BRL Hardy.

The company sells about 20,000 cases a year of Blackstone's Sonoma Reserve wines, Feeley said.

Constellation owns more than a dozen wineries in California, including Simi in Healdsburg and Clos du Bois in Geyserville.