Jackson Family Wines is making its first foray into Oregon, where it is negotiating to buy a substantial chunk of vineyards in the Willamette Valley, according to sources with knowledge of the deal.

The acquisition could be game changer for the Oregon wine industry, where the industry's most powerful players have yet to make significant investments.

Oregon's largest winery, King Estate, sells 250,000 cases per year. By comparison, Santa Rosa-based Jackson Family Wines sold 5.5 million cases of wine last year, according to Wine Business Monthly. About 41,500 tons of grapes were crushed into wine in Oregon in 2011, compared to 3.3 million tons crushed in California.

Bill Foley, proprietor of Chalk Hill, Sebastiani and more than a dozen other wineries, also is investing in Oregon. He said he has a deal to buy a winery, tasting room and 15-acre vineyard there.

Tom Danowski, executive director at the Oregon Wine Board, declined to provide information on the Jackson Family Wines acquisition because the deal was not yet finalized.

"You never know how it will turn out, but overall it should be real positive," Danowski said. "They've been very diligent and, I think, serious about the effort to find the vineyard acreage that works best for them. As it all comes together I'm sure they'll be welcomed."

Communications staff from Jackson Family Wines declined to provide details.

"Jackson Family Wines does not discuss rumors or speculation," Aimee Sands, senior communications manager, said in a statement. "However, as specialists in cool-climate varietals we're always focused on exploring the finest growing regions for pinot noir and chardonnay, and the Willamette Valley has an excellent reputation."

One of the vineyards targeted by the Santa Rosa company is owned by Commonfund, a Connecticut-based institutional investor that serves nonprofit organizations, educational endowments and pension funds, sources said.

The Zena Crown vineyard, which spans 250 acres in the Eola-Amity Hills AVA, was once owned in a partnership between the California Public Employees Retirement System and Premier Pacific Vineyards, which planted the vines, said Richard Wollack, managing trustee of Premier Pacific Vineyards. CalPERS sold the property in 2008 to Commonfund, he said.

"They're first-class vineyards, and Oregon is increasingly being recognized as America's Burgundy," Wollack said.

The Eola Amity Hills hold many vineyards, but only a handful of wineries that ship outside the state, said Pat Dudley, an owner of Bethel Heights Vineyard, a neighbor to Zena Crown. The possible sale is the talk of the town, and welcomed by the industry, she said.

"I think people find it intriguing, kind of gratifying, that our region is being discovered by some of the big players, because we've always thought that the Willamette Valley was the place to grow pinot noir in the New World," Dudley said.