OKLAHOMA CITY (AP) -- The state Regents for Higher Education approved an $18.5-million supplemental budget request.

It would cover debt service on bond obligations if state lottery revenue falls below expectations.

Higher education officials expected to receive about $28-million in lottery proceeds this year.

About $15-million was set aside for debt service and the balance was appropriated for scholarships and endowed chairs.

But regents have received only 67 percent of the lottery revenue as of April 14, leaving a balance of about $9.3-million.

Higher education officials asked state lottery representatives last week to begin making monthly payments instead of quarterly ones.

Regents say the request was refused and there is enough uncertainty about future collections to warrant a supplemental funding request.