BP (BP) and Apollo Global Management (APO) said Friday that they reached an agreement for Apollo-managed funds to purchase a 25% non-controlling stake in BP's 12% interest in the pipeline carrying natural gas from Azerbaijan through Turkey.

Under the agreement, Apollo will pay about $1 billion for a stake in BP TANAP, the subsidiary that holds BP's interest in the 1,800-kilometer pipeline, the companies said.

The transaction is anticipated to close in Q2, subject to regulatory and shareholder approvals, the companies said.

BP will remain the controlling shareholder of BP TANAP, the companies said.