SAExploration Holdings Inc. opened an exchange offer for $150 million, in aggregate principal amount, of senior notes, the company said May 19.

The outstanding 10% senior secured notes are due 2019. They were sold in a July 2014 private offering. They are being exchanged for an equivalent amount of 10% notes with the same due date that are registered.

The exchange offer will be open for at least thirty days, and is scheduled to close June 18 unless extended or closed earlier. Tenders of existing notes must be made before the exchange offer expires.

The exchange is not a new transaction, the company said, adding that it is being made to satisfy registration rights agreement obligations for the outstanding notes.

U.S. Bank NA is the exchange agent.

Oilfield services company SAExploration Holdings Inc. is based in Calgary, Alberta.