Ty Wright/Bloomberg News

Noble Energy has agreed to pay $3.4 billion for a 50 percent stake in Consol Energy’s venture in the huge Marcellus shale formation, reflecting the strong demand for natural gas assets.

Under the terms of the deal, Noble will team up with Consol on its 663,350-acre project in the Marcellus shale in West Virginia and Pennsylvania, and will pay $2.13 billion to Consol in drilling costs.

Shale formations, sedimentary rock from which natural gas and oil can be extracted through a technique called hydraulic fracturing, or fracking, have been at the center of many energy deals in recent months, despite scrutiny of the method by politicians and environmental activists.

In June, Marathon Oil agreed to pay $3.5 billion for assets in the Eagle Ford shale formation in south Texas owned by a joint venture with Kohlberg Kravis Roberts.

Progress Energy sold a 50 percent stake in its North Montney venture in British Columbia to the Malaysian state oil company Petronas for nearly $1.1. billion the following day.

With the joint development venture, Noble and Consol plan to quadruple the number of drilling rigs in the Marcellus formation to 16 horizontal rigs by 2015. Noble will also pay $160 million for Consol’s existing wells and $59 million for half of Consol’s gathering assets.

The deal represents the latest effort by major oil and natural gas producers to expand into the Marcellus formation, a giant deposit of carbonaceous shale beneath parts of Ohio, West Virginia, Pennsylvania, and New York. Several large swaths of the area changed hands last year. In the largest deal, Royal Dutch Shell bought the drilling rights to 650,000 net acres from East Resources for $4.7 billion in cash.

Teaming up with Noble will allow Consol to speed the development of the Marcellus portion it bought from Dominion Resources for $3.48 billion in 2010. That deal was said to increase Consol’s natural gas reserves by more than 50 percent, to about 3 trillion cubic feet.

“We are extremely pleased to have Noble Energy as our partner in the Marcellus,” J. Brett Harvey, Consol’s chairman and chief executive officer, said in a statement. “This agreement will benefit the regional economy, the communities in which we operate, our employees and our respective companies. Together we will be able to accelerate the development of this significant resource safely, efficiently and economically.”

The deal is expected to close at the end of September. Consol was advised by Jefferies & Company and represented by the law firms Vinson & Elkins and Wachtell, Lipton, Rosen & Katz.