Italian billionaire Gianluigi Aponte’s family-run business is emerging as the lead investor of a group seeking to buy 43 ports from Hong Kong tycoon Li Ka-shing, people familiar with the matter said, a deal that’s been fiercely opposed by China over US involvement.

The Aponte family’s Geneva-based Terminal Investment Ltd., known as TiL, will be the sole owner of all the ports after the deal is completed except for two in Panama that would be controlled by BlackRock Inc., the people said, asking not to be identified discussing previously unreported details of the deal’s structure.

The US investment firm’s unit Global Infrastructure Partners will own 51% of the two ports along the Panama Canal while TiL will hold the remaining 49%, the people said. The facilities at the strategic waterway account for about 4% of the total value of the deal, which will net Li’s CK Hutchison Holdings Ltd. more than $19 billion in cash once sealed, one of the people said.

The deal is still pending due diligence, tax and accounting checks, as well as approval from regulators where the ports are located, the people said. The buyers have committed to keeping the ports’ management and current operating rules unchanged, where the majority of the terminals are for common users and are open for all shipping lines without discrimination, one of the people said.

Considerations are ongoing and details including the final structure and ownership of the consortium may still change, the people said.

The new details provide clarity on how the consortium will divide the port assets in the deal that has become Li’s most geopolitically challenging ever, having drawn China’s ire and Panama’s scrutiny. While Beijing has piled pressure on the 96-year-old tycoon to back away from the transaction that involves assets coveted by US President Donald Trump, Panama’s top auditor has accused CK Hutchison of wrongdoings. The company has denied the allegations.

BlackRock and Singaporean state investor GIC Pte have a combined minority ownership of about 30% in TiL, the people said. The port operator runs more than 70 container terminals, including upcoming projects, in 31 countries, according to its website.

The Aponte family’s MSC Mediterranean Shipping Co., which controls TiL, declined to comment. CK Hutchison and BlackRock didn’t immediately respond to requests for comments.

When the sale was first announced on March 4, the buyer group was referred to as the BlackRock-TiL consortium that included BlackRock, Global Infrastructure Partners and TiL. The announcement didn’t elaborate on the structure of the consortium.

Although the deal was open to under 10 bidders, the consortium backed by the Apontes was chosen partly because the clan was an old acquaintance of Li, and CK Hutchison thought the ports would be in good hands, said one of the people.

Ships can use the Panama Canal like a regular highway, regardless of who owns the ports. Terminal owners also need to operate the facilities according to the laws and contract terms of different countries where the ports are located.

While work on the deal is progressing, the parties have already missed their initial target of nailing the Panama part of the sale by April 2.

CK Hutchison has kept its ports in Hong Kong and mainland China. The two regions contribute about 12% of total revenue for the Cayman Islands-registered company.