Westmoreland said in a federal Securities and Exchange Commission filing in March that Oxford will sell 1.3 million tons to AEP starting in 2016, 1.2 million tons in 2017 and 750,000 tons in 2018, the final year under the long-term agreement.

In addition, Oxford has the “right of first refusal” to supply up to 400,000 tons in 2016, 300,000 tons in 2017 and 200,000 tons in 2018 to AEP’s Conesville generating station in Ohio. That could increase the total transaction to more than 4 million tons.