Nexi and SIA unveiled on Monday a long-awaited accord to create a dominant domestic Italian payments group with 1.8 billion euros ($2 billion) in annual revenue and a market value of 15 billion euros.

The stake being placed by Nexi's private equity owners comprises 84 million shares, the banks managing the offer said. Based on Nexi's closing price on Tuesday, it is worth around 1.4 billion euros.

The deal is expected to be priced at 15.50 euros and books are covered at that price, the bookrunners said.

Mercury UK - the vehicle of private equity firms Bain Capital, Advent International and Clessidra - will hold 20.1% of Nexi after the placement. That is equivalent to a 14% stake in the Nexi-SIA merged group. Under a lockup agreement, Mercury UK will not sell any shares in Nexi for six months after the closing of the merger and it will retain at least half of the stake for a further six months after that. Barclays, Citi and Goldman Sachs are acting as joint global coordinators and joint bookrunners for the deal, with Rothschild as financial adviser.

(Reporting by Elisa Anzolin, Additional reporting by Aakriti Bhalla in Bengaluru; Editing by Valentina Za and Peter Cooney)