Occidental Petroleum to buy stake in pipeline

The deal is expected to close in the next 30 to 45 days.

No near-term change to the board of directors is expected as a result of the transaction with Los Angeles-based Occidental, which also agreed to invest in common units as the master limited partnership raises capital.

A master limited partnership, or MLP, is a limited partnership that trades publicly, thus combining the tax benefits of a limited partnership with the liquidity of a publicly traded company. Most of its cash flow must come from real estate, commodities or natural resources. An MLP's general partner, which may have numerous owners, is responsible for the MLP's management.

Plains shares rose $1.68, or 3.8 percent, to $46.43; Occidental shares fell 71 cents to $90.72.