Kroger Co , the biggest U.S. supermarket chain, raised its forecast for 2011 earnings, helped by strong sales increases at established stores.

The company now expects earnings for the year of $1.95 to $2.00 a share, up from its previous forecast of $1.85 to $1.95. Analysts on average forecast $1.96, according to Thomson Reuters I/B/E/S.

Shares of the company, which owns chains that include Ralphs and Food 4 Less, rose 2.6 percent in premarket trading.

Kroger's fiscal third-quarter net income was $195.9 million, or 33 cents per share, compared with $202.2 million, or 32 cents per share, in the year-earlier quarter.

Analysts, on average, were looking for 32 cents a share.

Sales, including fuel, rose 10.3 percent to $20.6 billion. Sales at established stores rose 5 percent, excluding fuel.

(Reporting by Brad Dorfman; editing by John Wallace)