April 15 (Reuters) - EQT will sell 40% interest in its non-operated natural gas assets in northeast Pennsylvania to Equinor USA in exchange for Equinor's onshore asset in the Appalachian basin and $500 million in cash, the companies said on Monday.

Non-operating positions give holders a cut from the hydrocarbons sold without taking charge of drilling or other operations, although they must contribute their share of costs.

Natural gas prices have pummeled to three-year lows, forcing producers to curb output and spending on drilling activity.

Reuters reported last year that EQT was exploring a sale of a portfolio of minority stakes in wells in Pennsylvania's Marcellus shale formation.

"We plan to opportunistically divest the remaining portion of our non-operated assets in northeast Pennsylvania," EQT CEO Toby Rice said on Monday.

EQT's plan to exit the position comes as the company tries to accelerate cutting its $5.9 billion debt pile and boost shareholder returns.

"This (deal) also means that we have now fully exited all operated positions onshore U.S.," Philippe Mathieu, executive vice president for Exploration and Production International at Equinor, said. (Reporting by Seher Dareen in Bengaluru; Editing by Shounak Dasgupta)