The NASDAQ OMX Group, Inc. (NASDAQ: NDAQ) is an American multinational financial services corporation that owns and operates the NASDAQ stock market and eight European stock exchanges in the Nordic and Baltic regions and Armenia under the NASDAQ OMX banner. It is headquartered in New York City, and its president and chief executive is Robert Greifeld.

In December 2005, the London Stock Exchange Group (LSE) rejected a £1.6 billion takeover offer from Macquarie Bank. The LSE described the offer as "derisory." It then received a bid in March 2006 for £2.4 billion from NASDAQ, which was also rejected by the LSE. NASDAQ later pulled its bid, and less than two weeks later on April 11, 2006, struck a deal with LSE's largest shareholder, Ameriprise Financial's Threadneedle Asset Management unit, to acquire all of that firm's stake, consisting of 35.4 million shares, at £11.75 per share. NASDAQ also purchased 2.69 million additional shares, resulting in a total stake of 15%. While the seller of those shares was undisclosed, it occurred simultaneously with a sale by Scottish Widows of 2.69 million shares. The move was seen as an effort to force LSE to negotiate either a partnership or eventual merger, as well as to block other suitors such as NYSE Euronext, owner of the New York Stock Exchange.