WASHINGTON • A 78-year-old billionaire investor expected to be nominated US secretary of commerce by President-elect Donald Trump has been characterised as a "vulture" by some critics, but a saviour of failing US industries by supporters.

In any case, Mr Wilbur Ross is expected to come under heavy scrutiny if Mr Trump does indeed tap him.

"He might be the second-most complicated person in the administration to vet, behind the President-elect himself," Politico reported Mr Norman Eisen - a Brookings Institution visiting fellow and one-time chief ethics lawyer to President Barack Obama - as saying.

Mr Ross heads WL Ross, a private equity firm, and has a net worth estimated by Forbes to be US$2.9 billion (S$4.2 billion). As a generous presidential campaign contributor, he helped argue Mr Trump's campaign vow to renegotiate "bad trade deals" and punish China and Mexico by imposing "defensive tariffs" on their imports.

Yet Mr Ross told the Financial Times a week ago that he is not anti-trade and wants to encourage international commerce as long as trade deals are structured to benefit the US.

"Free trade doesn't mean dumb trade," he said. "Cutting our balance of payments deficit doesn't mean slapping on 45 per cent tariffs on everything from China.

"But here is the key issue: We should treat ourselves as the world's biggest customer and treat nations that are selling to us as suppliers to us."

With his history of taking over the remnants of companies that have been bankrupted partly because of foreign competition, Mr Ross also agrees with Mr Trump that China and other countries are taking advantage of US industry.

One concern, though, is that his restructuring of failing industries has sometimes compromised the safety of workers. In one case, the Politico website said it may have contributed to the deaths of 12 miners in a 2005 explosion at a West Virginia mine run by a coal company he had just cobbled together from bankrupt firms.

On the other hand, his purchase of some of the largest steel mills in the US in the early 2000s was credited with saving manufacturing jobs, though many of the mills have since closed.

While Mr Ross is widely expected to be nominated for the commerce post by Mr Trump, reports in some media on Thursday that he had confirmed that he had indeed been named proved to be false, having been based on a tweet from a fake Twitter account.

Mr Ross' numerous foreign and domestic investments, and other business dealings could also complicate his confirmation hearings.

Like Mr Trump, he would have to avoid potential conflicts of interest by ending his personal involvement in business.