The United Kingdom’s BG Group has agreed to pay $1.01 billion for a 50 percent stake in Texas company Exco Recources’s Haynesville shale gas joint venture.

Exco shares were up over eight percent on the news.

BG Group will be large player in East Texas and North Louisiana’s upstream assets for $650 million in cash and $400 million in capital commitments.

In return the U.K.-based gas player will share control of 6 billion cubic feet of gas reserves that could grow to 18.6 Bcf if some of the 1,600 undrilled drill sites prove prolific.