Oklahomas House of Representatives today passed a bill increasing the states contribution to the Oklahoma Teachers Retirement System, Oklahoma City. The increase will be phased in over the next six years and will result in an additional annual contribution to the system of $66.5 million. The $6 billion system is one of the five most underfunded state-run pension plans in the country, according to the systems website. It is about 51.4% funded, said Bill Puckett, chief investment officer. The bill will go to Gov. Frank Keating for approval.