CalPERS has won court permission to proceed with a $1 billion lawsuit against the three big Wall Street credit-rating agencies. A San Francisco Superior Court judge rejected a request by the rating agencies to toss out the CalPERS suit, which stems from a string of failed investments. "We are pleased with this result," said CalPERS spokesman Brad Pacheco. In the suit, the California Public Employees' Retirement System says it relied on ridiculously high ratings when it poured more than $1 billion into the deals, known as structured investment vehicles.