A worker at SEIU, Local 721, was disciplined Tuesday for urging union members to sign the pension overhaul petition being circulated by former Mayor Richard Riordan with fake names and addresses to try to invalidate the proposal.

Officials with the Service Employee International Union, which represents city workers, said the memo from Paul Kim was not authorized and is contrary to the union's policies.

"SEIU Local 721 in no way recommends that its members or anyone else falsify signatures," spokesman Ian Thompson said. "We are against that kind of behavior."

Riordan is seeking to a get a measure on the May ballot that would overhaul the city's pension system, including moving new workers into a 401(k)-style plan.