A coalition of more than 20 public employee and union groups is forming to fight California Gov. Arnold Schwarzenegger's proposal to make new public-sector employees join defined contribution plans. Dave Low, assistant director, government relations, for the California School Employees Association today told the board of the $180.3 billion California Public Employees' Retirement System, Sacramento, that the group is getting strong responses from local groups as well as the financial community. Mr. Low said Mr. Schwarzenegger broke an agreement he made last year to halt efforts to adopt a two-tiered retirement system for the duration of his term. "It appears to us that negotiated agreements with Gov. Schwarzenegger have the shelf life of lettuce," he said. Experts believe Mr. Schwarzenegger's proposal will go to voters in a November ballot initiative.