By Ben Lefebvre and Daniel Gilbert Chesapeake Energy Corp. (CHK) will lay off 70 workers in its North Texas office as low natural gas prices force the company to trim production in the region, the company said Tuesday. The layoffs, representing 8% of Chesapeake's work force in Fort Worth and Cleburne, Texas, come as Chesapeake struggles to balance its books after years of spending on land leases. With natural-gas prices only recently rebounding from a decade low, the Oklahoma-based company has sold $6.6 billion in assets so far this year in the hopes of cutting its long-term debt to $9.5 billion. The layoffs were "not a surprise, given historic low natural gas prices and our company's strategy to redeploy assets to more economically promising fields," Chesapeake said in a letter to employees announcing the layoffs. Write to Ben Lefebvre at ben.lefebvre@dowjones.com