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Feb 21 (Reuters) - ConocoPhillips COP.N said on Friday it would sell its interests in the Ursa and Europa Fields to Shell SHEL.L for $735 million, as part of the shale producer's plan to streamline its portfolio.

The company has been looking to offload non-core assets to help lower debt after its $22.5 billion takeover of rival Marathon Oil. Earlier this month, Conoco said it was divesting its non-core Lower 48 assets for $600 million.

"This (Shell) transaction reflects our ongoing commitment to further strengthen our portfolio by divesting non-core assets and shows significant progress toward our $2 billion disposition target," ConocoPhillips said.

The transaction is expected to close by the end of the second quarter of 2025 after which Shell's working interest in Ursa would increase to 61.35% from 45.4%.

Shell said the acquisition expands its ownership in an established long-producing asset that "generates robust free cash flow, while also providing more options for growth".

Shares of ConocoPhillips were down about 2% in afternoon trade, pressured by declining crude prices.

(Reporting by Vallari Srivastava in Bengaluru; Editing by Krishna Chandra Eluri)

((Srivastava.Vallari@thomsonreuters.com;))