Ford Motor Co. (NYSE: F) won back its investment-grade credit rating Tuesday from Fitch Ratings on the automaker's significantly improved financial performance, balance sheet repair and product portfolio improvement.

Fitch, which downgraded Ford's credit rating to junk six years ago, lifted the No. 2 U.S. automaker from BB+, the agency's highest non-investment grade rating, to BBB-, its lowest investment-grade rating. The rating outlook for both Ford and Ford Credit is stable.

Dearborn, Mich.-based Ford was the only one of the nation's Big Three automakers to avoid bankruptcy in 2006, in part because of its aggressive borrowing, which climbed to $23 billion.

Since the last recession, Ford's management has been heavily focused on increasing profitability, growing liquidity, lowering debt and reducing the company's pension obligations, the ratings agency said in a statement.

Fitch believes that the work that has been accomplished has put the company in a solid position to withstand the significant cyclical and secular pressures faced by the global auto industry.

The agency cited the nearly $10 billion in cash the No. 2 U.S. automaker had on hand at the end of last year as sufficient to withstand a downturn in the global car business.

News of the upgraded lifted the price of Ford's bonds, Barron's said.

The other two U.S. credit rating agencies, Standard & Poor's and Moody's Investors Service, still have Ford's credit rating at a non-investment grade level.

Shares closed up six cents to $11.39.