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May 2 (Reuters) - U.S. oil and gas producer Noble Energy Inc said on Tuesday it would sell all its natural gas production assets in the Marcellus shale field for $1.23 billion, as it shifts focus to liquids-rich, higher-margin assets.
The company said its interest in CONE Midstream Partners LP , which owns natural gas pipelines, was not part of the deal.
Noble did not name the buyer.
Oil and gas companies have been pushing into oil-rich basins such as the Permian in West Texas, in a bid to increase exposure to the low-cost drilling, following a more than two year slump in oil prices.
Earlier this year, Noble bought smaller rival Clayton Williams Energy Inc for about $2.7 billion to enhance its presence in the Permian.
The Marcellus deal comprises an upfront cash payment of $1.13 billion and $100 million more contingent on natural gas prices.
Noble said proceeds from the deal will be used to pay down debt it had incurred to buy Clayton Williams.
The company expects to close the deal by the end of the second quarter.
BofA Merrill Lynch was Noble's financial adviser while Porter & Hedges provided legal counsel. (Reporting by Sayantani Ghosh in Bengaluru; Editing by Shounak Dasgupta and Sai Sachin Ravikumar)