Exxon Mobil will cut nearly 400 jobs in Texas following its purchase of shale producer Pioneer Natural Resources, according to a regulatory filing.

A regulatory filing shows more than 90% of layoffs are at Pioneer’s former headquarters in Irving, Texas with the rest being workers in Midland.

Spring-based Exxon Mobil Corp. (NYSE: XOM) is laying off 397 Texas employees as a result of its $59.5 billion acquisition of Pioneer Natural Resources, the company said in a Worker Adjustment and Retraining Notification Act letter sent to the Texas Workforce Commission.

Exxon will reduce the headcount at Pioneer Natural Resources by some 397 over the next two years, reducing the number of employees by 20%. The move follows Exxon’s megadeal for the acquisition of Pioneer, which had a final price tag of around $62 billion.

Exxon Mobil (NYSE:XOM) expects to lay off 397 employees from Pioneer Natural Resources, according to a notice to the Texas Workforce Commission released on Wednesday, after purchasing the company for $63B earlier this year.