ALBANY, N.Y.—Chevron Corp. has asked New York's ethics commission to investigate state Comptroller Thomas DiNapoli, claiming that as trustee of the $150 billion state pension fund he improperly pushed to settle an $18 billion Ecuadoran court claim for environmental damage in the Amazon rainforest.

San Ramon, Calif.-based Chevron says the state fund owns more than $800 million in Chevron stock and that DiNapoli received more than $60,000 in campaign contributions from plaintiffs in the Ecuadoran lawsuit. The energy giant also said DiNapoli's office received offers of trips to Ecuador, political benefits and access to celebrities.

Calls to DiNapoli's office were not immediately returned.

He has said he joined with 39 other big investors in May to urge Chevron to settle the legal fight.

The company says liability was settled by remediation and an old agreement with Ecuador.