Apollo Global Management Inc. and Brookfield Asset Management Inc. are among parties that made first-round bids for a potential multibillion-dollar stake in Saudi Aramco’s natural gas pipeline network, according to people familiar with the matter.

BlackRock Inc., EIG Global Energy Partners LLC and Global Infrastructure Partners also submitted non-binding offers for the asset late last week, the people said, asking not to be identified as the matter is private.

Aramco is seeking more than $15 billion for the gas pipeline stake in one of the largest divestments by the energy giant, the people said. The state-owned company will inform suitors whether they made it to the next round of bidding in the coming days, according to the people.

No final decisions have been made and Aramco could still decide to retain the asset, the people said. Other contenders could also emerge for the stake, with some of the bidders likely to join forces given the size of the asset, the people said.

Representatives for Aramco, BlackRock, Brookfield, EIG and GIP declined to comment, while a spokesperson for Apollo didn’t immediately provide comment.

The world’s largest oil company is planning to raise tens of billions of dollars by selling more stakes in its businesses as it seeks to maintain a US$75 billion annual dividend, a key source of funding for Saudi Arabia’s government. A group of investors led by EIG Global agreed to invest US$12.4 billion in Aramco’s oil pipelines in June, in one of the largest infrastructure transactions this year.

A deal involving the gas pipeline could be structured in a similar way to the oil pipeline transaction, where investors bought a minority stake in a new Aramco subsidiary with leasing rights over the assets, people with knowledge of the matter have said.

Aramco’s Master Gas System is a network of pipelines connecting its production with processing sites throughout the kingdom. The infrastructure has a capacity of about 9.6 billion cubic feet of gas per day, according to Aramco’s annual report.