The Wall Street Journal report on Wednesday cited people familiar with the matter and comes amid a sweeping review of HSBC's operations worldwide by interim chief executive Noel Quinn.

"We have just received a denial of the rumours by the general management," the union source told Reuters.

HSBC declined to comment.

The bank's French retail business has around 270 branches and could be worth around 1 to 1.5 billion euros (892.42 million pounds - 1.34 billion pounds), analysts at KBW estimated. It employs up to 3,000 staff out of 8,000 in France overall, according to the bank's annual report.

Another union source said that union representatives had a meeting with the bank's local management last Monday where ways of getting the business out of the "red" were discussed.

The bank is closing 9 branches and considered whether it needed to close more. However, the possibility of selling the business was not on the table during the meeting, the union source said.

Quinn took over at HSBC after the shock ousting of John Flint on Aug. 4. He has between 6 to 12 months from that date to make his case for the permanent role, Chairman Mark Tucker said, so he is expected to move quickly to try and improve HSBC returns.

(Reporting by Maya Nikolaeva in Paris and Lawrence White in London; Editing by Richard Lough and Elaine Hardcastle)

By Maya Nikolaeva and Lawrence White