A federal judge has approved the sale of oil and gas producer Rex Energy to a Moon Township-based energy company.

PennEnergy Resources said in a news release Thursday afternoon that its bid to buy Rex for $600.5 million in cash had been approved by the U.S. Bankruptcy Court for the Western District of Pennsylvania. The company said the deal is expected to close Sept. 28.

PennEnergy’s acquisition of Rex, which has 210 active wells in Butler County, will create a company that operates 329 horizontal producing shale gas wells, according to the company’s news release, primarily in Butler, Beaver and Armstrong counties.

PennEnergy expects the acquisition to make it the 10th largest natural gas producer in Pennsylvania, and the third largest producer headquartered in the state.

Rex, which has its regional headquarters in Cranberry Township, entered Chapter 11 bankruptcy in May after defaulting on debt payments. It has struggled in recent years with low market prices for natural gas.

Left unaddressed in PennEnergy’s news release were several lawsuits filed against Rex by landowner groups alleging the company failed to live up to lease deals.

PennEnergy’s sale agreement lays out slightly more than $1 million that would be split by those plaintiffs.

Among the suits levied against the company, three arose from groups in Butler County: the Gasch Group, The Dressler Family and the MacKrell Estate.

Each alleged lease violations on the part of Rex and challenged “cure amounts” the company proposed in a July 6 filing, each saying they were due more than the company claimed.

- The Gasch Group, a collection of landowners, filed a suit against the company in December of 2014 claiming that Rex improperly deducted operating costs from their royalties starting back in 2011 and refused to pay royalties on gas used by “third-party midstream companies to run their operations.”

- The Dressler Family filed a similar suit against Rex in June of 2017, claiming the company began deducting “certain electric fees that it allegedly incurred while processing and gas at processing plant” back in 2014. This was in violation of the lease agreement, the Dressler claim alleges.

- The MacKrell lawsuit began in February but the events leading up to it started in August of 2016, when, the suit claims, Rex violated the lease agreement after the company’s “failure to commence operations” within the time frame laid out in their agreement.