Northern Oil and Gas Inc. entered into two separate debt exchange agreements with holders of its 8% senior notes due 2020, reducing the company's debt by $13.5 million of notes.

Including other debt exchanges announced since the start of June, the new agreements would bring the amount of Northern Oil and Gas' retired notes to $77.2 million, which permanently cuts interest expenses by $6.2 million annually, according to an Aug. 7 news release.

In one exchange, Northern would make an initial issuance of 3,244,657 common shares to an investor in exchange for almost $12 million of notes, with an option to issue additional shares depending on Northern's stock price performance over a certain period. The other exchange entails an issuance of about $1.6 million in common shares to a separate investor in exchange for $1.5 million of notes.

Northern Oil and Gas is an exploration and production company with core operations in the Williston Basin's Bakken Shale and Three Forks play in North Dakota and Montana.