Shares of Calabasas-based Countrywide Financial Corp. rose more than 4 percent on Friday on reports that the mortgage giant was in talks with Bank of America about a possible merger or alliance.

The reports, which first surfaced in the Financial Times early Friday, said the talks could lead to Bank of America the nation’s largest consumer bank acquiring Countrywide, the nation’s largest mortgage lender. Such a deal would catapult Charlotte, N.C.-based Bank of America into the top ranks of mortgage lenders, though it might run into antitrust issues.

The talks also could lead to a joint venture or alliance between the two firms, with Bank of America being able to offer home mortgages through its huge branch network and Countrywide getting the support of B of A’s larger balance sheet to ride out the slowdown in the mortgage industry.

Neither Countrywide nor Bank of America would comment on the deal reports.

Countrywide was founded by Angelo Mozilo in 1969. Last year, Mozilo last year agreed to remain as the company’s chief executive through at least 2009.

Countrywide’s stock closed on Friday at $42 per share.