Last week the business empire of Hong Kong's richest man, Li Ka-shing, sold most of its ports operations -- including those in the canal -- to a US-led consortium following pressure from US President Donald Trump.

In a statement, CK Hutchison Holdings said it would offload a 90-percent stake in the Panama Ports Company and sell a slew of other non-Chinese ports to a group led by giant asset manager BlackRock for $19 billion in cash.

On Saturday, the Hong Kong and Macao Work Office -- the Beijing-based authority in charge of Hong Kong affairs -- reposted a newspaper editorial titled "Great entrepreneurs have always been outstanding patriots".

The article, originally published by the Beijing-backed newspaper Ta Kung Pao in Hong Kong, said many Chinese people have questioned "how so many important ports can be so easily handed over to ill-meaning American forces".

"If (entrepreneurs) fail to see the true nature of American politicians... and choose to dance with them, perhaps they can do a mega-deal and get rich for a while, but in the end they have no future and will be scorned by history," the piece read.

The same article was also republished in full on Saturday by the Liaison Office, the top Beijing authority based in Hong Kong.

- 'Choose a side' -

CK Hutchison stocks in Hong Kong plunged more than six percent on Friday after Chinese authorities republished an op-ed telling the company to choose "which side it stands on".

That older article appeared in the commentary section of Thursday's Ta Kung Pao, which is owned by a subsidiary of the Liaison Office.

In contrast, Saturday's editorial was excerpted on the front page and its full text ran on page three.

The paper's website published three more opinion pieces by outside contributors on Sunday morning, all critical of the deal.

CK Hutchison has not responded to AFP's request for comment.

For months, Trump has complained that China controls the Panama Canal and that American vessels were overcharged for using it, even refusing to rule out a military invasion of Panama to "take back" the vital waterway.

Before the sale, CK Hutchison's subsidiary in Panama had managed two of the five ports at the canal -- one at Cristobal and the other at Balboa -- via a government concession since 1997.

The ports transaction was "purely commercial... and wholly unrelated to recent political news", co-managing director Frank Sixt said when the deal was announced.

China's foreign ministry spokesperson Lin Jian declined to comment on the deal earlier this month.

The Hong Kong government has said it "never interfered in the commercial operation of Hong Kong companies".

CK Hutchison Holdings is one of Hong Kong's largest conglomerates, spanning finance, retail, infrastructure, telecoms and logistics.