Japan's Mitsubishi UFJ Financial Group is in talks to buy Bank of America Merrill Lynch out of a private banking joint venture operated by the pair, The Wall Street Journal (Japan) reports.

The move would involve Mitsubishi buying out a 49 per cent stake in the business, which is worth some $488 million, the news service said, citing people with direct knowledge of the discussion.

The deal could be made as early as next month, with one source reportedly saying that it will likely allow the Tokyo lender to strengthen ties with partner Morgan Stanley in asset management and private banking.

As well as controlling over a fifth of voting rights of Morgan Stanley, Mitsubishi operates three separate joint ventures with the bank and has ambitions to build up the duo’s alliance, the report said.

Meanwhile, if confirmed, the move for Merrill would follow the announcement in August that BofA is selling its international wealth management businesses based outside of the US -  not including Mitsubishi UFJ Merrill Lynch PB Securities - to Switzerland's Julius Baer.

BofA had not responded to a request for comment on the move in time for publication.