UPDATE 1-Citi says no wrongdoing as Greece probes debt email

* Greece says probe launched into Citi email

* Citi says no wrongdoing by the bank or employees

* Email cites "increased noise" over debt restructuring

(Adds detail, background)

By Lefteris Papadimas and Douwe Miedema

ATHENS/LONDON, April 21 (Reuters) - Citigroup (C.N) said it had done nothing wrong after Greece launched a probe into market rumours about an imminent restructuring of the country's sovereign debt that had hit Greek bank stocks.

Greek officials said on Thursday that an investigation launched by a Greek prosecutor late on Wednesday was prompted by an e-mail sent by a Citigroup employee.

"We are cooperating with the authorities and do not consider there to have been any wrongdoing by Citi or its employees," Citi said in an emailed statement.

Greek bank stocks .FTATBNK dropped 4.6 percent on Wednesday on what traders said were rumours spread by email that the country would soon restructure its debt.

A Finance Ministry official later told Reuters that the e-mail in question was sent by a Citigroup analyst, and that the ministry had asked the prosecutor to take up the issue.

"The prosecutor is investigating this particular email and the person who sent it because it spread false rumours with an effect on the stock market," a court official said, speaking on the condition of anonymity.

Greece has repeatedly said it would not restructure the country's debt, in stark defiance of market sentiment that a restructuring was increasingly likely.

The email, the content of which was forwarded to Reuters, cites "increased noise" over a Greek debt restructuring "as early as this Easter weekend", and notes how spreads in the bond market were widening.

(Reporting by Douwe Miedema; Editing by Erica Billingham)