A source familiar with BHP Billiton's plans for some of its Gulf of Mexico properties said that BHP had indicated a willingness to sell its 50% shareholding in the Cascade field, one of several discoveries in the Walker Ridge area of the US Gulf that industry experts believe could become a prolific oil producing region.

"If the question is 'are we actively marketing it?' the answer is no, but we'll certainly take a look at any inquiry we have for our assets," said a BHP spokesman.

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