"The stock slump is flushing out buyers," said the banker. "Noble has been very focused on staying independent but it's hard to see it staying that way now after the price fall and accounting issues," he said.
The banker declined to name the potential suitors as the talks were confidential. Other M&A bankers who have worked with Chinese state-owned companies mentioned China Minmetals, Brightoil Petroleum and Singapore state investor Temasek Holdings as potentially interested parties in acquiring Noble.
Bankers cautioned though that there were no active discussions between Noble and potential suitors and it was unclear whether any interested parties would actually proceed with a proposal.
The sources declined to be identified as the discussions are confidential. Brightoil declined to comment, while a Beijing-based spokesman for China Minmetals said he was not aware of any such plans. Temasek declined to comment on "speculation".
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Noble, in response to questions from Reuters, declined to comment on any likely suitors, adding its focus remained on "ensuring that we run our day to day business as efficiently as possible".
Elman, 75, who began his career in a scrap yard in England at the age of 15, has transformed Noble into one of the world's biggest suppliers of commodities from coal and iron ore to coffee. The energy business accounts for the bulk of its revenue and profits.
"There is a scarcity value attached to Noble because there are hardly any listed commodity players," said the Singapore banker.
Last year, a Temasek-led consortium made a buyout offer for agricultural commodities trader Olam International , more than a year after short seller Muddy Waters raised questions about Olam's finances, sparking a stock slump.
Elman, who has recently raised his stake to nearly 21 percent in Noble, though is unlikely to be pressured into a sale, despite the slump in prices of several commodities, people familiar with his thinking said.
"Elman is known to hold a multi-decade view on commodity prices. He is not the one to sell at the bottom of the cycle," said one person who has previously advised Noble.
It was not immediately clear what Noble's other significant shareholders think about a sale. China Investment (CIC), Orbis Investment, Templeton and INVESCO cumulatively own more than 27 percent of the company, Reuters data shows.
Bankers say CIC's 9.4 percent stake in Noble would make it easier for a Chinese state-owned company to propose an offer.
CIC and Templeton didn't respond to a Reuters query, while INVESCO and Orbis declined to comment.