Under the deal - expected to close in the fourth quarter - Nyse Technologies will pay $1.675 per share of common stock, a 95% premium on Wednesday's closing price. The $144 million price-tag includes preferred stock.

Upon closing, Nyfix's software business and Marketplace, its FIX-based community, will become part of Nyse Technologies' offerings. Nyfix Marketplace connects more than 1000 global trading counterparties to one another via more than 9000 fully managed FIX-based messaging channels.

The exchange was less forthcoming on plans for the Nyfix Transactions Services business, including the Millennium dark pool, saying only it will "explore various alternatives".

Earlier this month Nyfix posted a Q2 net loss of $3.8 million, although this was an improvement on a $6.8 million loss for the same period the previous year. Revenues for the quarter were $26.6 million, down on the $28.6 million in Q2 2008.

Once the acquisition is complete, the Nyfix business will report to Nyse Technologies CEO, Stanley Young. Nyfix CEO Howard Edelstein will stay on through the close of the transaction and Bob Moitoso will continue to lead the FIX business.

Says Young: "Nyfix is a natural extension of our connectivity business and fits nicely into our SFTI Integrated Partner Solutions, which currently enables hundreds of technology providers to offer value added products and services to participating firms. The synergies will be particularly apparent to the pre-trade buy- and sell-side communities, which will benefit from a broad combination of technology assets and connections for efficient end-to-end transaction processing."

The acquisition - subject to approval by Nyfix shareholders and customary regulatory approvals - is expected to be accretive to Nyse Euronext 2010 earnings, excluding one-time deal and restructuring costs.