NextDecade (NEXT) said Tuesday that it has executed a 20-year liquefied natural gas sale and purchase agreement with a unit of Saudi Arabian national oil company Aramco.

NextDecade said the agreement states that the Aramco unit will buy 1.2 million metric tons per annum of LNG for 20 years on a free-on-board basis at a price indexed to Henry Hub, subject to a positive final investment decision on Train 4 of the Rio Grande LNG facility near Brownsville, Texas.

Shares of NextDecade were up 14% in recent Tuesday premarket activity.