(AP) DENVER With less than three weeks to go before the end of the session, lawmakers are scrambling to reach a compromise on the state retirement plan, which is facing an estimated $11 billion shortfall to cover current members and retirees.

If they fail, Gov. Bill Owens has threatened to call them back into session to finish the job after the session ends on May 10.

This Wednesday, the Senate State, Veterans and Military Affairs Committee is scheduled to take up two proposals to fix the program, one sponsored by Republicans and the other by Democrats.

The Public Employees Retirement Association covers 68,000 retirees and 175,000 active workers in state and local governments. Some have blamed its projected shortfall on the decline of the stock market in 2001 and the associated recession. Owens wants a two-tier system that would leave current employees under the defined-benefit plan, which guarantees benefits, while putting future employees under a defined-contribution plan, similar to 401(k) programs.

Under a defined-contribution plan, the state would contribute to employees' retirement funds and individual employees would determine how their money is invested. Owens also wants to replace the current board with financial advisers.

Sen. Paula Sandoval, D-Denver, sponsor of one plan (Senate Bill 174) said she wants a compromise that allows some but not all retirees to choose a defined-contribution plan, and to keep some of the PERA members on the board.

"I think we'll end up in the middle. It will be expanded to some groups, but it won't be open to everyone," Sandoval said.

Sen. Dave Owen, R-Greeley, sponsor of the other proposal (Senate Bill 162) supported by Owens, said the governor also wants to raise the retirement age from 55 to 60 to be more in line with private pension systems.

State Treasurer Mike Coffman, who warned several years ago that the program was in danger of going broke, said the state needs a long-term solution to avoid putting it off on another generation.