The stake, which is made of 48.5 million shares, has a value of around 600 million euros (510.2 million pounds), Mercury UK said in a statement, adding it would sell it through an accelerated book building.

Mercury UK currently holds a stake of around 60.1% in Nexi, Italy's stock exchange regulator website showed.

The exact price at which the shares will be sold will be communicated at the end of the transaction.

(Reporting by Elisa Anzolin; writing by Francesca Landini, editing by Giulia Segreti)