Moody's Investors Service raises Ford’s credit rating to investment grade, a move that returns control of the Blue Oval logo to the auto maker.

Ford, facing financial difficulty in 2006, raised $23.5 billion in liquidity by pledging as security most of its domestic assets, including the Ford Blue Oval, F-150 and Mustang trademarks and $5 billion of unsecured convertible debt.

In a note to investors, Moody’s says it is raising Ford’s rating because of the auto maker’s “position in North America, its robust liquidity position and our expectation (it) will continue to embrace sound operating and financial disciplines.

“We believe that these strengths will enable Ford to maintain an investment-grade profile in the face of the sector’s ongoing cyclicality and weakness in the European market.”

The auto maker’s rating was boosted from Baa3 to Ba2, while lending arm Ford Motor Credit’s rating was increased to Baa3 from Ba1.

Chairman Bill Ford in a statement says the upgrade was the result of hard work by all employees and notes the emotional impact of signing away the rights to the Blue Oval.

“When we pledged the Ford Blue Oval as part of the loan package, we were not just pledging an asset,” he says. “We pledged our heritage. Getting the Ford Blue Oval back feels amazing, and it is one of the best days that I can remember.”