Californian wines dominate the premium category of wine costing 15 U.S. dollars or more in the United States market, as consumers are willing to pay more to drink quality wine, according to a study about the state's wine industry released on Thursday.

It is good news for the wine industry here because sales of wine costing 15 dollars or more have been on the rise, said MKF Research, which carried out the study for the San Francisco-based Wine Institute, a public policy advocacy group for Californian wineries.

Authors of the study said that American shoppers who used to spend 10 dollars for a bottle of wine for dinner are now willing to pay an extra 5 dollars.

California has cornered about 85 percent of the U.S. market for these premium wines, according to the study based on 2005 sales figures.

The wine industry analysts said that California's vintners are commanding higher prices because of agricultural advantages, such as a fabulous soil and favorable weather conditions that allow local vineyards to grow better grapes than those in other areas, including the Bordeaux region in France.

Meanwhile, Californian wines are losing out to imports in the under-8-dollar segment of the market that often attracts younger buyers.

Imports in 2005 accounted for about 27 percent of the total volume of wine consumed in the United States, up from 18 percent in 1998, the study said. There were about 81 million cases of imported wine in 2005, up from 40 million in 1998.

The last time imported wines ware as popular as their local counterparts was the mid-1980s, when foreign wines had about 26 percent of the market share, mostly because of the strong dollar that made imports cheap.

Italian wines had the largest market share of the U.S. market in 2005, followed by Australia, whose Yellow Tail wines with a price tag of 5 dollars a bottle were popular among American drinkers. About 8 million cases of Yellow Tail were sold in the United States last year.

France, which held the second position in wine exports to the U.S., based on 2002 data, slipped to third in the new study.

Altogether, wine produced in California poured some 52 billion dollars into the state economy last year, including wine sales, industry wages and money from tourist visits to vineyards and wineries, according to the study.