Shares in Rolfe & Nolan continue to trade 23% higher at 75 pence after the UK-based supplier of technology to the derivatives industry confirmed that it had received a bid approach late last week.
In a brief statement noting the rise in the company's share price, Rolfe & Nolan states: "The board of Rolfe & Nolan can confirm that it has received an approach that may or may not lead to an offer being made for the company."
Credit Lyonnais is acting on behalf of the vendor while talks are ongoing.
No further details were disclosed.
Analysts have fingered US-based OnExchange, a supplier of Java-based back office technology to clearing houses, banks, and brokerage firms, as the most likely source of the offer.
The London Clearing House (LCH) last month selected onExchange's J2EE-based Extensible Clearing System (ECS) as the basis for its clearing of over-the-counter (OTC) power transactions executed on the European Energy Derivatives Exchange (Endex), which is set to launch later this year.