Williams Partners LP (NYSE: WPZ) has completed its acquisition of an additional 24.5% interest in the Gulfstream interstate gas pipeline system from Williams, Tulsa, Okla., (NYSE: WMB) for $330 million.

Gulfstream is a 745-mile interstate gas pipeline system that extends from the Mobile Bay area to markets in Florida.

Williams Partners now owns a 49% interest in the Gulfstream system, while Williams directly holds a 1% interest. Spectra Energy Corp. and its subsidiaries own the additional 50% interest.

Williams Partners' total consideration for the 24.5% interest in Gulfstream included $297 million in cash and $33 million in WPZ limited-partner and general-partner units.

Williams Partners funded the cash portion of the acquisition with its revolving credit facility. The transaction is expected to be immediately accretive to distributable cash flow for Williams Partners, on a per-unit basis for the partnership's unitholders.