Sources: KNOC A Partner in El Paso E&P Acquisition

NEW YORK - The Korea National Oil Corporation is a part of the group that has agreed to pay $7.15 billion for El Paso Corp.'s exploration-and-production business, according to people familiar with the matter.

Known as KNOC, the government-backed company's involvement in the buyout was not disclosed when the deal was announced last month by a group of investors led by Apollo Global Management LLC.

At the time, Riverstone Holdings LLC., an energy focused private-equity firm, and Len Blavatnik's Access Industries were named as partners. It is unclear what stake each partner will have in EP Energy, as the business is now called.

A spokeswoman for Apollo declined to comment, as did a spokesman for Riverstone. A representative for KNOC could not immediately be reached.

KNOC's participation comes as national oil companies, particularly those in Asia, are increasingly staking claim to North America's oil and gas renaissance.

In November KNOC teamed up with the trading and construction unit of Samsung Group to buy Parallel Petroleum from Apollo for $771.5 million. Parallel operates oil and gas fields in Texas and New Mexico.

In addition to those assets, KNOC has stakes in shallow-water fields off Louisiana and Alabama as well as a one-third interest in a south Texas shale field operated by Anadarko Petroleum Corp.

EP Energy's assets are spread throughout the U.S. and include fields in Egypt and the deep waters off Brazil.

El Paso planned last year to spin off EP Energy as a separate public company. But in November, before it separated the unit from its pipeline business, Houston-based El Paso agreed to be acquired by Kinder Morgan Inc. for $21.1 billion.

Kinder Morgan said at the onset that it would sell the exploration and production business, aiming to close the deal this spring, around the time the larger merger is finalized.