(Reuters) - BlackRock ( BLK ) could hit another roadblock in its attempt to secure control of two flagship ports near the Panama Canal once the Central American country releases an audit on a 25-year concession granted to Hong Kong-based CK Hutchison ( CKHUF ).

Final signature of the deal in Panama, part of a broader $22.8 billion transaction between a BlackRock ( BLK )-led group and CK Hutchison ( CKHUF ) including over 40 ports in 23 countries, is expected to be delayed as criticism grows in China, sources told Reuters last week.

The deal's definitive documentation was initially expected to be signed by April 2, BlackRock ( BLK ) and CK Hutchison ( CKHUF ) said last month when they announced the deal.

As China's market regulator begins an antitrust review on the deal, Panama's government is requesting documents from CK Hutchison ( CKHUF ), a telecoms-to-retail conglomerate owned by tycoon Li Ka-shing, to complete an audit on the concession.

Panama's Maritime Authority also asked BlackRock ( BLK ) and CK Hutchison ( CKHUF ) to provide details of their deal, which must ultimately be green-lit by Panama.

The deal includes 90% of the Panama Ports Company, which operates the Balboa and Cristobal ports at either end of the Panama Canal.

WHAT COULD THE AUDIT FIND?

The Panama ports audit was announced in January by the Comptroller General office as "the most important" of a series of reviews of key infrastructure concessions in Panama. Comptroller general Anel Flores said last week that results are expected in the coming 'days or weeks.'

Flores has criticized previous audits, including one completed before CK Hutchison's ( CKHUF ) concession was renewed in 2021, saying they were limited to confirming the fulfillment of operational goals.

"We'll begin a severe, strong audit of those books and company," he said earlier this year.

Flores has also complained about the 'poor yield' of the contract for Panama and the slow delivery of documents requested from CK Hutchison ( CKHUF ).

In February, Panama's Attorney General released a binding opinion finding that the port contract was unconstitutional. Panama's Supreme Court will have the last word on that.

If the Comptroller General finds irregularities in the concession renewal or the Supreme Court declares the contract to be unconstitutional, the concession could be revoked, complicating the BlackRock-CK Hutchison deal and possibly creating grounds for international arbitration, lawyers and experts have said.

WOULD THE DEAL EASE TRUMP'S PRESSURE?

U.S. President Donald Trump has celebrated the BlackRock-CK Hutchison deal, while China and pro-Beijing voices have criticized it, thrusting the firms involved and the Panamanian ports into the fray of the U.S.-China trade war.

However, any hurdles to the deal increase the risk of a hardening of Trump's policy towards the canal.

Since taking office in January, Trump has escalated his threats of controlling places he says could better serve U.S. interests, like the Panama Canal and Greenland.

The ports are not part of the canal. However, American officials and politicians have said CK Hutchison's ( CKHUF ) control of them, along with other concessions to Chinese firms in Panama, represents a security risk for the canal's operation.

CK Hutchison ( CKHUF ) has said the sale of the ports was purely commercial and unrelated to politics. Panama says the canal is operating in a fair and secure way, granting equal access to vessels from all origins.

WHAT IS THE VIEW FROM CHINA?

Pro-Beijing media have published a series of commentaries criticizing CK Hutchison's ( CKHUF ) deal, depicting it as a betrayal of China and a "perfect cooperation" with the U.S. strategy to contain China.

The pressure on CK Hutchison ( CKHUF ) has deepened concerns that Hong Kong's edge as a financial hub will erode further amid geopolitical tensions.

WHAT IS IN IT FOR BLACKROCK?

The purchase is in line with BlackRock's ( BLK ) recent investment drive in infrastructure, and it secures the fund manager a strong position near an essential global trade hub.

The broader deal including many other ports worldwide could give BlackRock ( BLK ) control of 10.4% of global container throughput, making it the world's third largest port operator, Chinese state media reported.

The deal has also been described as helping BlackRock ( BLK ) and CEO Larry Fink win political capital with Republicans, who in some states have restricted or banned BlackRock ( BLK ) from managing retirement or treasury funds over the company's policies on environmental, social and corporate governance (ESG) investing.

Some Republicans were reconsidering BlackRock ( BLK ) bans after Trump praised the deal.