Chesapeake, which is also being probed by the DOJ and states over possible antitrust violations related to land purchases, said it is responding to the subpoenas, according to a filing with the U.S. Securities and Exchange Commission.

A spokesman for the Oklahoma City, Oklahoma company declined to comment on Thursday.

Chesapeake faces a slew of lawsuits from landowners and others who allege the company has underpaid royalties for produced and sold natural gas and natural gas liquids through the use of improper deductions or below-market pricing.

Chesapeake said in its quarterly SEC filing on Wednesday that it has resolved a number of those claims and has also prevailed in some lawsuits.

Shares of Chesapeake fell 3.4 percent to $21.98 in midday New York Stock Exchange trading. That compares with a 2 percent decline in the SIG Oil Exploration and Production Index.

(Reporting by Anna Driver; Editing by Terry Wade and Leslie Adler)

By Anna Driver