* Cuomo issues subpoenas to investment firms and agents

* Cuomo and 36 states form pension fund abuse task force

* Agents, consultants and others dodge reporting rules

* New Mexico, New York City and state disclose agents (Adds details)

By Joan Gralla

NEW YORK, May 1 (Reuters) - New York state's pension kickback probe expanded on Friday as its attorney general said he issued more than 100 subpoenas to investment firms and their agents who do business with the state's pension fund.

Attorney General Andrew Cuomo told reporters 40 percent to 50 percent of the agents that deal with the state and New York City public pension funds are not licensed or registered.

Cuomo, a Democrat, said New York and 36 other states created a task force to root out pension fund abuse and devise national reforms. California, Florida, Illinois, Iowa and Kansas said they are joining the task force, and others may sign on later.

The probe, which the Securities and Exchange Commission has joined, is another effort to stamp out graft and "pay to play" practices involving gifts or campaign donations to win state and local government contracts. The inquiry has focused on ties connecting money managers, politicians, lawyers, lobbyists and pension officials.