SAN FRANCISCO — Lawyers for CalPERS are cheering a state appellate ruling they hope has set them up for a win in a long-running suit against Moody’s Investors Service Inc. and Standard & Poor’s.

A First District Court of Appeal panel ruled unanimously Tuesday that the California Public Employees’ Retirement System may proceed with its 2009 case against the rating agencies for allegedly inflating credit ratings for certain structured investment vehicles and enticing the pension fund to sink money into risky investments.