May 20 (Reuters) - The California Public Employees'

Retirement System said on Monday it will vote against all 12

director nominees at Exxon, citing the company's lawsuit

against activist investors.

The system known as CalPERS said in a letter to its members

posted online that if successful, Exxon's legal action "could

diminish the role-and the rights-of every investor in improving

a company's bottom line."

Exxon's shareholder meeting is set for May 29.