SM Energy Co. (SM) opened an offer to exchange all of its outstanding registered 6.125% senior notes due 2022, the company said June 10. The aggregate principal amount is $600 million.

The registered notes will be exchanged for identical notes issued on Nov. 17, 2014 in a private placement. The registered notes will be exchanged pursuant to a registration rights agreement for the private placement notes.

Provisions on transfer restrictions, registration rights and additional interest do not apply to the registered notes.

The exchange offer is scheduled to close July 9, unless extended.

U.S. Bank NA is the exchange agent.

Denver-based SM Energy Co. explores and develops oil and natural gas across the U.S.