Plains All American Pipeline L.P. said that a wholly owned subsidiary of Occidental Petroleum Corp. plans to acquire a 10 percent equity interest in its general partner directly from the existing owners.

Houston-based Plains is a publicly traded master limited partnership that transports, stores and markets crude oil, refined oil products, liquefied petroleum gas and natural gas products. The partnership though a separate entity also develops and operates natural gas storage facilities.

The purchase price was not disclosed in the Wednesday announcement, and Los Angeles-based Occidental had not issued its own release on the deal by mid-morning. The deal is expected to close within the next 30 to 45 days.

Shares of Occidental were up 61 cents, or 0.6 percent, to $92 at mid-morning on the New York Stock Exchange.