The London Stock Exchange Group completed a $2.3 billion acquisition of Borsa Italiana on Monday even as takeover talks swirled about the British exchange.
The company said it listed an additional 79.5 million shares, giving it a market value of 4.6 billion pounds ($9.4 billion).
"We will accelerate growth through the provision of a better and wider range of products and services to an increasingly international customer base," said LSE Chief Executive Clara Furse. "This merger will help us to crystallize our vision to be the world's capital market."
Shares in the LSE rose 0.2% to 1,646 pence ($33.70).
The 1.63 billion euro-takeover was a coup for Furse and the London exchange after fending off bids by the Nasdaq Stock Market , Australia's Macquarie Bank, Euronext, Germany's Deutsche Boerse and Sweden's OM Gruppen.
But last month the Qatari Investment Authority bought a 20% stake in the LSE, and Borse Dubai bought a 28% bloc from Nasdaq -- raising speculation of a potential bid by either.
Neither Borse Dubai nor the Qatar Investment group immediately signaled any intention to attempt a takeover -- though Qatar cautioned that it could do so if someone else moved against the London exchange.