Coterra Energy Inc. has added more interests related to its $3.95 billion Permian Basin deal with Franklin Mountain Energy and Avant Natural Resources.

Coterra will buy an additional 1,650 net royalty acres from Sandia Minerals LLC for $43 million, according to a Dec. 31 Securities and Exchange Commission (SEC) filing. The royalty interests were excluded from its initial Franklin Mountain acquisition. Sandia’s interests are owned by Franklin Mountain Royalty Investments, according to the SEC filing.

The deal to acquire Sandia’s interests increases the Franklin Mountain purchase price to $1.543 billion. Franklin Mountain’s November deal with Coterra includes 40.89 million shares of Coterra stock worth about $1 billion. The separate Avant transaction is valued at $1.45 billion.

The Franklin Mountain and Avant deals will add between 400 and 550 net locations, mostly within Lea County, New Mexico.