Noble Energy Inc. on Tuesday said it has closed its previously announced sale of oil and natural gas properties in Oklahoma and Texas to an affiliate of Unit Corp. for about $594 million.

The sale to Unit Corp.’s United Petroleum Co. subsidiary includes about 84,000 net acres primarily in the Granite Wash, Cleveland and Marmaton plays in western Oklahoma and the Texas Panhandle. The estimated proved reserves of the properties were 44 million barrels of oil equivalent, which represents a 38 percent increase to Unit Petroleum’s proved reserves at the end of last year.

Unit, based in Tulsa, Okla., said it plans to begin drilling horizontal wells in the Granite Wash area with one to two rigs in January, increasing to six to seven rigs by the end of 2013.

The acquisition was funded with proceeds from a $400 million debt offering that was closed in mid-July, with the rest of the cost initially covered through bank debt.

Shares of Houston-based Noble fell 52 cents to $94.53 in morning trading, while shares of Unit slipped 29 cents to $44.80.