Affiliates of Occidental Petroleum are selling 19 million common units of Western Midstream Partners LP for $685.9 million, Western Midstream said on Aug. 12.

The underwritten secondary public offering is expected to close Aug. 14, subject to customary closing conditions.

Western Midstream Holdings LLC, the general partner of Western Midstream Partners LP, is a wholly-owned subsidiary of Occidental Petroleum Corp.

Western Midstream Partners is not selling any common units in the offering and will not receive any proceeds from the sale of common units in the offering, the company said.

As the underwriter, Barclays has been granted  a 30-day option to purchase up to 2.85 million additional common units from the selling unitholders at the public offering price less underwriting discounts and commissions, Western said.

Barclays is acting as the sole book-running manager for the offering.