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May 2 (Reuters) - I Squared Capital is in talks to acquire a majority stake in the Matterhorn Express natural gas pipeline, according to people familiar with the matter.

The infrastructure-focused investment firm has been speaking with potential investors that would help fund the potential purchase, the people said.

I Squared is buying its position from WhiteWater Midstream, they added. WhiteWater currently owns 67.5% of Matterhorn, although it was unclear from the people whether the investment firm was buying out WhiteWater's entire position.

The other owners of Matterhorn are EnLink Midstream, Devon Energy N> and MPLX <MPLX.N>. It was unclear whether some or all of their stakes were included in the piece being acquired by I Squared.

The people cautioned no deal was guaranteed and spoke on condition of anonymity to discuss private information.

I Squared and WhiteWater did not respond to requests for comment. ONEOK <OKE.N>, which owns EnLink, Devon and MPLX also did not respond to comment requests.

Bloomberg News earlier on Friday reported that I Squared was in talks to buy a majority stake that would value the Matterhorn Express Pipeline at more than $5 billion including debt, citing people familiar with the matter.

The Matterhorn pipeline carries natural gas from the Permian basin to the outskirts of Houston. The 580-mile pipeline was designed to carry up to 2.5 billion cubic feet per day of gas, according to its website.

(Reporting by David French in New York; Editing by David Gregorio)

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