Dec 9 (Reuters) - The Pennsylvania Attorney General's office on Wednesday said it filed a lawsuit against Chesapeake Energy Corp and its affiliates over claims that the companies underpaid landowners who leased land for fracking.

The lawsuit alleges that the Oklahoma City- based oil and natural gas producer tricked landowners into signing leases in the Marcellus Shale region and paid royalties less than agreed upon.

The lawsuit, filed in the Bradford County Court, seeks restitution for thousands of consumers, civil penalties and legal costs.

In fracking, water, sand and chemicals are injected into underground shale formations to produce oil and gas reserves that were otherwise inaccessible.

(Reporting by Apeksha Nair in Bengaluru; Editing by Lisa Shumaker)