Intercontinental Exchange (ICE) said on Tuesday it was considering making a counter-offer for the London Stock Exchange Group, potentially putting it head-to-head with rival bidder Deutsche Boerse.
ICE said no approach had been made so far and no decision had been taken as to whether to pursue such an offer.
"There can be no certainty that any offer will be made, nor as to the terms on which any offer will be made. A further announcement will be made as appropriate," the group said. Shares of the LSE Group surged 7.4 percent by 11 a.m. London time Tuesday on the news.
Last week, the LSE said in a statement that it was holding discussions with Deutsche Boerse about a potential all-share merger. The deal would potentially create a larger European player that could compete on the global stage against firms in Asia and the U.S.
Deutsche Boerse failed in an attempt to take over its British counterpart in late 2004. However, a new deal was back in the offing last week. The possible new deal would form a holding company with Deutsche Boerse shareholders having a 54.4 percent stake and LSE shareholders having a 45.6 percent stake.
Carsten Kengeter, the Deutsche Boerse chief executive, is being lined up to run the day-to-day operations of the new company, according to a report by Reuters last week.
Following the rival bid, however, the German company said that merger talks with LSE were still on the table and said it has taken note of the approach by ICE.
The London Stock Exchange Group declined to comment when contacted by CNBC on Tuesday.