OKLAHOMA CITY (Reuters) - The Oklahoma House approved a bill on Wednesday that prohibits health insurance companies from offering coverage of elective abortions in standard policies sold in the state.

Under the bill, approved by an 84-10 vote, people seeking abortion coverage could do so only by paying a separate premium for optional supplemental coverage.

The bill has already passed the Oklahoma Senate by a 36-10 vote and now heads to Governor Mary Fallin.

State Representative Mike Ritze, a physician from Broken Arrow, said the bill keeps pro-life Oklahomans from violating their beliefs when they buy standard insurance policies.

"Oklahomans who believe in the sanctity of life should not be forced to indirectly subsidize the abortion industry," he said.

Abortion restrictions such as this one have been opposed by groups including Planned Parenthood, which contend limitations being pushed across the country are denying women the right to decide whether and if to have children.

Lawmakers in 23 states this year have attempted to restrict abortion insurance coverage, according to a report by the Guttmacher Institute, a nonprofit think-tank that studies women's reproductive health issues.

Some bills call for abortion restrictions on all private insurance plans while others seek restrictions only on policies offered through the state insurance exchanges envisioned under federal health care reform, the Guttmacher report said.

(Reporting by Steve Olafson; Editing by Corrie MacLaggan and Jerry Norton)