The mouthpiece newspaper of China's Communist Party has blasted Hong Kong tycoon Li Ka-shing as "ungrateful" for selling assets on the mainland with the world's second-largest economy facing headwinds.

The 87-year-old, nicknamed "Superman" for his sharp business acumen, has been offloading major property investments in China -- where growth slowed to a 24-year low last year and has continued to weaken this year -- after investing heavily there in the 1990s.

The move, combined with his selling of assets in Hong Kong, has fuelled speculation that the richest man in Asia is losing confidence in the Greater China region.

The People's Daily said on a verified social media account that China's opening up, vast market and favourable policies had been "the key cornerstone" of Li's success, yet he was now leaving his benefactor in the lurch.

"He shared the prosperity while we had good times but could not beat the odds together with us now that we have difficulties. This is indeed unacceptable emotionally," it said in a commentary Sunday on its account on China's mobile messaging application WeChat, a less formal platform than the printed newspaper itself.

While admitting Li's move may have a "negative impact" on confidence in China, the article sought to downplay concerns.

"China's economy accounts for more than 12 percent of the world's total... Can the withdrawal of a single businessman affect the fundamentals?" it said.

"We don't need to worry that no investors will come after Li Ka-shing.

"What we can do is not to condescend to persuade him to stay or to hurl invectives out of outrage, but to build the country better to make today's departure tomorrow's regret," it said.

Li, who is currently worth $32.9 billion according to the Bloomberg Billionaires index, started out in business as a plastic flower-maker.

He has been reshuffling his business empire since the start of this year and earlier this month announced the merger of his utilities firms, part of an overhaul seen as paving the way for him to hand over the reins to his eldest son Victor, 51, after he retires.

In one of his recent overseas purchases, Li in March acquired British telecom giant O2 from Spain's Telefonica for $15.2 billion.