A deadline is swiftly approaching for Southwestern Energy Co.’s (NYSE: SWN) purchase of Chesapeake Energy Inc.’s (NYSE: CHK) Marcellus and Utica shale assets for $5.375 billion.

While it’s hardly a nail-biter, it’s still technically possible that the third largest E&P deal of 2014 could slip from Southwestern’s grasp. The transaction is subject to consent of co-owner Statoil ASA (NYSE: STO). The Norwegian company also has a 30-day preferential right to purchase the property.

“We expect a potential update on the financing and timing of the transaction any time in the next several business days,” said Daniel P. Katzenberg, analyst, Baird Energy, in a Nov. 19 report.

The clock runs out this week.

Statoil has not made a statement about the deal and did not respond to a request for comment.

On Oct. 16, the day the deal was announced, Steve Mueller, Southwestern chairman, president and CEO, said the agreement between Chesapeake and Statoil can kill the deal.

“They have 30 days to decide if they want to buy this acreage for the $5.4 billion,” Mueller said.

Chesapeake agreed to sell its southern Marcellus assets and a portion of the eastern Utica in West Virginia to Southwestern. In an August presentation, Statoil said it was exploring new midstream and downstream opportunities in the southern Marcellus.

Southwestern’s purchase and sale agreement requires Chesapeake to send a letter to Statoil within 10 business days. The letter is to say that Statoil has the right to purchase the property and right of first refusal.

Credit Suisse analyst Arun Jayaram noted in late October that Southwestern has declined to comment about the acquisition.

“The company did, however, mention that it does not view the recent acquisition as a call on natural gas, but rather an investment in top of the food chain acreage,” Jayaram said. “Management continues to stress that it has built in the low price environment into its strategic model, including a further challenge to basis differentials in fiscal year 2015.”

Chesapeake parted with 413,000 net acres and about 1,500 wells—435 in the Marcellus and Utica formations in northern West Virginia and southern Pennsylvania. Related property, plant and equipment are included.

Southwestern said the wells include 256 operated and producing Marcellus and Utica horizontal wells and an additional 179 nonoperated or nonproducing Marcellus and Utica horizontal wells.

The transaction will also give Southwestern a portion of Chesapeake's firm transportation and processing capacity commitments. Based on that capacity and expected future commitments Southwestern's preliminary plan is to begin with four to six rigs in 2015 and increase to 11 rigs by 2017.

The company estimates it can drill for a minimum of 20 years at an 11-rig pace. By the end of 2017, the company’s reserve mix is estimated to be about one third each for the Fayetteville, northeast Marcellus and the newly acquired West Virginia and Pennsylvania properties.

Statoil has moved aggressively in the past in the Marcellus.

Statoil entered the Marcellus in 2008 through a partnership with Chesapeake. Since then the company has pursued a targeted and stepwise growth strategy.

In December 2012, Statoil purchased 70,000 operated net acres in the liquids-rich portion of the Marcellus for $590 million and became an operator.

"The U.S. unconventional plays hold a substantial resource base and represent an increasingly important part of future energy supplies. Statoil is further strengthening its U.S. onshore portfolio by acquiring additional acreage in the valuable liquid rich parts of the Marcellus Shale in Ohio and West Virginia," Torstein Hole, Statoil U.S. onshore senior vice president, said at the time.

The company reported a net loss of about $710 million for the third quarter of 2014 due to accounting charges.