Jan 30 (Reuters) - Nvidia's NVDA.O plan to invest up to $100 billion in OpenAI to help it train and run its latest artificial-intelligence models has stalled after some inside the chip giant expressed doubts about the deal, the Wall Street Journal reported on Friday.

The chipmaker in September announced plans to invest up to $100 billion in OpenAI in a deal that would have given the ChatGPT maker the cash and access it needs to buy advanced chips that are key to maintaining its dominance in an increasingly competitive landscape.

The Journal, citing people familiar with the matter, said the companies are rethinking the future of their partnership, and the latest discussions include an equity investment of tens of billions of dollars as part of OpenAI's current funding round.

Nvidia CEO Jensen Huang has privately emphasized to industry associates in recent months that the original $100 billion agreement was non-binding and not finalized, the report said.

Huang has also privately criticized what he has described as a lack of discipline in OpenAI's business approach and expressed concern about the competition it faces from the likes of Alphabet's GOOGL.O Google and Anthropic, the WSJ added.

"We have been OpenAI's preferred partner for the last 10 years. We look forward to continuing to work together," an Nvidia spokesperson said in an emailed statement to Reuters.

OpenAI did not immediately respond to Reuters' request for comment.

Big Tech companies and investors such as SoftBank Group Corp 9984.T are racing to forge partnerships with OpenAI - which is spending heavily on data centers - betting closer ties with the startup would give them a competitive edge in the AI race.

Amazon AMZN.O is in talks to invest dozens of billions in OpenAI and the figure could be as high as $50 billion, Reuters reported on Thursday.

OpenAI is looking to raise up to $100 billion in funding, valuing it at about $830 billion, Reuters has previously reported.