The New Mexico Supreme Court has ruled in favor of two oil companies in a multi-million dollar dispute over royalties owed for oil and natural gas production on state land.

At issue in Friday’s ruling was how royalty payments should be calculated under decades-old lease provisions.

The high court upheld a district court decision in favor of ConocoPhillips Co. and Burlington Resources Oil and Gas Co.

The companies had challenged assessments by the State Land Office that ConocoPhillips owed $18.9 million and Burlington Resources $5.6 million for underpayment of royalties.

The Land Office manages leases for oil and gas production as well as livestock grazing on state lands.