The London Stock Exchange has seen profits surge by just under a third, cheered on by strong growth from capital markets and its information systems.
The British bourse said adjusted pre-tax profits climbed 31% to £643.4 million, up from £491.7 million in 2014 , as its Italian post trade operation and interest-rate swap platform SwapClear bolstered its performance.
The LSE said talks were ongoing over a possible £20 billion merger with Germany's Deutsche Borse to create one of the biggest exchange companies in the world.
But the owner of the New York Stock Exchange - the Intercontinental Exchange (Ice) - has threatened to gatecrash the bid despite stressing it has not yet approached LSE's board to make an offer.
LSE's total revenues rose sharply - up 78% to £2.3 billion for 2015 - driven by its buy-out of the Russell Group.
Shares were up just under 1%, as it hiked the full-year dividend by 20% to 36p per share.
Chief executive Xavier Rolet said the group was making "excellent progress" in its quest to be the leader in global markets infrastructure.
He added: "We have delivered underlying growth in each of our business areas and maintained good cost control."
Mr Rolet added that "despite the volatility" its commitment to the emerging markets was as "strong as ever" and was working on a study for the UK and Chinese governments which could lead to a connection between the London and Shanghai markets.
The strong financial performance comes after LSE put further flesh on the bon es of its potential deal with Deutsche Borse at the end of last month.
The pair's previous moves to join forces failed in 2000 and 2004-5 when talks collapsed.
The new deal on the table would be an all-share merger, with LSE shareholders holding 45.6% of the group and Deutsche Borse the remaining 54.4%.
However, the tie-up would see Mr Rolet step down, with Deutsche Borse boss Carsten Kengeter becoming chief executive of the combined company and LSE's Donald Brydon taking up the role of chairman.
The current chairman of Deutsche Borse Joachim Faber would become deputy chairman and senior independent director, with LSE's David Warren retaining his position as chief financial officer.
The combined business will run headquarters in London and Frankfurt.
But the bourses also warned that the project could be "put at risk" if Britain votes to leave the European Union.
The London Stock Exchange is one of the world's oldest stock exchanges and can trace its history back more than 300 years.
The wider LSE Group was formed in October 2007 when the London Stock Exchange merged with Milan stock exchange Borsa Italiana.
It has completed a series of deals since then, the biggest of which was its £ 1.6 billion takeover of American stock index and asset management business Frank Russell.