A federal judge in Kentucky has rejected class-action status in a lawsuit accusing Countrywide Bank of charging African-American and Hispanic borrowers more for home loans than Caucasian borrowers.

U.S. District Judge John Heyburn II on Thursday ruled that Countrywide's policy put a great deal of discretion in the hands of individual loan officers, leaving too many variables at play to conclude that "even unconscious discriminatory motive or thought similarly animated thousands of mortgage rate decisions."

"However, the idea that thousands of loan officers in hundreds of separate locations around the country would exercise their discretion in a similarly discriminatory fashion as to each purported class member defies belief," Heyburn wrote. "Whether an individual loan officer or a single office did so, might be a different question."

A dozen people sued Countrywide, which is now owned by Charlotte, N.C.-based Bank of America, in 2008, claiming they and others were treated differently from other customers looking for a home loan between 2005 and 2007.