ExxonMobil, Corp., the largest U.S. oil company, is seeking partners for four concessions in the Podlasie natural-gas shale basin in Poland.

The company owns the concessions and will retain its role as operator, according to a posting on a Schlumberger, Ltd.- operated website today.

Exxon said the area covers about 1 million gross acres. An exploration well in the Minsk Mazowiecki concession scheduled for this month is intended to help evaluate the gas potential, the company said. Exxon said a seismic survey has been acquired on the Wolomin concession. The other sections are known as Legionowo and Wodynie-Lukow.

Exxon and Chevron Corp. are looking to tap Poland’s unconventional gas reservoirs, which can require fracturing of rock formations to help gas to flow. Poland last year called on the European Union to give more weight to shale gas in its energy policy to reduce the reliance on imports.

Exxon’s posting shows the company is seeking offers to buy up to 49 percent of its equity in the areas, with preference given to offers with full corporate approval. An online data room is set to open Feb. 16 and close April 13. Offer submissions are due on April 15.

Margaret Ross, an Exxon spokeswoman, said in an e-mail that it’s Exxon’s “practice not to discuss commercial details or negotiations.”