Mercury UK, a vehicle of private equity firms that hold a controlling stake in Nexi, has placed an 8.8% stake in the Italian payments group at a price of 14.2 euros (12.63 pounds) per share, a Milan-based trader said.

The price represents a 7.2% discount to Nexi's closing price of 15.305 euros a share on Tuesday.

The sale comes as Nexi advances in talks with rival SIA over a potential merger to create an Italian champion in the fast-growing payments sector.

Mercury UK, which announced the placement through an accelerated bookbuilding procedure late on Tuesday, held around 52.12% of Nexi, according to the company website.

Barclays, Goldman Sachs and HSBC managed the offering.

(Reporting by Maria Pia Quaglia; writing by Valentina Za)