The Hong Kong-based conglomerate made the comment the day after exclusive talks ended with the consortium, led by US investment firm BlackRock and Italian billionaire Gianluigi Aponte's family-run shipping company MSC.

The parties in March agreed a preliminary deal for 43 ports in 23 countries, including two ports along the strategically important Panama Canal.

Ports operator China COSCO Shipping Corp is looking to join the consortium, a person with knowledge of the matter told Reuters.

BlackRock declined to comment. MSC and COSCO did not immediately respond to requests for comment.

The price of CK Hutchison shares rose 1.6 percent on Monday, outpacing a 0.9 percent gain in the benchmark Hang Seng Index.

CK Hutchison said changes to the composition of the consortium and structure of the transaction would be necessary to secure regulatory approval, and that it would allow as much time as needed to achieve that.

"The company has stated on several occasions that it will not proceed with any transaction that does not have the approval of all relevant authorities," CK Hutchison said in a filing to the Hong Kong Stock Exchange on Monday.

CK Hutchison would be open to bids from other parties now that exclusivity has ended, said a person with direct knowledge of the matter, who declined to be identified as they were not permitted to speak to media.

The company declined to comment beyond its exchange filing.

The development adds uncertainty to the deal, initiated after calls by US President Donald Trump for the Panama Canal to return to US control, drawing the ire of both Panama and China.

Trump hailed the deal as "reclaiming" the Panama Canal, after his administration previously called for the removal of what it said was Chinese ownership of ports along the canal.

The White House did not respond to a request for comment sent outside normal US business hours.

China's State Administration for Market Regulation said it would review the deal in accordance with the law to protect fair competition and safeguard public interests.

The regulator did not immediately respond to a faxed request for comment.

State-backed media, whose stance typically aligns with that of the government, criticized the deal, saying China had significant national interests in any transaction and that pursuit of the deal as it stands would be an act of betrayal.

CK Hutchison, in its statement, said any new investor must be a "significant" member of the consortium.

"This is an interesting development. A PRC [China] investor with majority control of the consortium sounds like a non-starter in my view. An investor with a less than 50 percent stake you would think should keep everyone happy," said strategist David Blennerhassett of Ballingal Investment Advisors, who publishes on SmartKarma.

Adding COSCO to the consortium should relieve some Chinese government concerns and enhance the likelihood of regulatory approval, JPMorgan said in a client note.

The US brokerage said it is possible that not all ports would be included in any new deal, particularly the two Panama ports, and that the buyer mix could change due to geopolitical concern, which in turn could change the final pricing.