The London Stock Exchange Group is likely to announce the sale of its French clearing arm this week, City A.M. understands.
The exchange entered exclusive talks with pan-European rival Euronext shortly before Christmas and the parties are understood to be nearing a deal worth around €500m (£425m).
The successful sale of LCH SA would be a significant step for the London Stock Exchange’s attempts to push through its £21bn merger with Deutsche Boerse.
EU competition regulator the European Commission is currently probing the deal, which is due to complete in the first half of this year, and has narrowed its focus on clearing.
The London Stock Exchange put LCH SA up for sale in September when the commission announced its in-depth investigation, anticipating clearing trouble.
The stock exchange, which appointed bankers at JP Morgan Cazenove to handle the deal, was aiming to announce an agreement before Christmas.
Despite itself opposing the London Stock Exchange-Deutsche Boerse tie-up, Euronext has always been seen as the favourite to land LCH SA, although US-based rivals such as CME Group and Nasdaq were also linked with the sale.