A federal judge has ruled that a shareholder lawsuit against Countrywide Financial Corp. executives and directors should go to trial, rejecting several arguments by the troubled mortgage lender to dismiss the case. In a ruling issued Tuesday, U.S. District Judge Mariana R. Pfaelzer in Los Angeles sided with several public pension funds, finding that their witnesses' accounts of Countrywide's business practices were compelling. Several witnesses gave persuasive accounts of Countrywide's business, including allegations that the company rewarded employees for boosting loan volume rather than for generating quality loans.