Moon-based Penn Energy is in the process of buying oil and gas producer Rex Energy Corp. for $600.5 million, according to the sales agreement between the two companies that was filed Monday.

The agreement, which must still be approved by a federal bankruptcy judge, includes a provision that would provide slightly more than $1 million to be divided among landowners currently suing Rex for unfulfilled lease obligations.

Rex Energy, based in State College, filed for Chapter 11 protection in May, after defaulting on a debt payment in April. The company also failed to deliver timely financial statements to lenders and failed to provide lenders with accurate notices of the company’s financial troubles, according to a Securities and Exchange Commission filing.

At the time, the company’s CEO, Tom Stabley, released a statement:

“We have undoubtedly made progress in addressing the realities of the global commodities market but require a more fulsome debt restructuring to overcome the immense pressures our business is facing. Ultimately, we decided that the best possible outcome was to put our remaining assets into the hands of owners with the financial strength necessary to position them for long-term growth and success.”

The company was founded in 2007 and has been shedding assets since 2012. It most recently sold off non-operated oil and gas assets in Centre, Clearfield and Westmoreland counties, according to earlier reports.

The company’s primary holdings, however, are in Butler County, according to records kept by the state Department of Environmental Protection. More than 75 percent of the company’s gas well permits were issued for Butler County, according to DEP, with 321 well permits issued on 76 well pads.

A company spokesman said in May that Rex has 212 active wells on 81 well pads in Pennsylvania, under the name RE Gas Dev LLC. In Butler County, 321 RE Gas Dev wells are in various states of activity, according to DEP; 210 are listed as active.

Rex has offices in Cranberry Township. Neither Rex nor Penn Energy responded Tuesday to requests for comment.

A hearing has been scheduled for Thursday in front of Judge Jeffrey Deller of the U.S. Bankruptcy Court in Pittsburgh to approve the purchase.