NYSE Euronext said on Thursday the trans-Atlantic stock exchange will buy NYFIX Inc for $144 million, to optimize trading efficiency.

NYSE Euronext offered $1.675 per share of common stock, a 95 percent premium over Wednesday's closing price of NYFIX on the Nasdaq. The deal also includes the acquisition of all preferred shares.

NYFIX, whose shares rose 90 percent in early Nasdaq trading, designs systems that process financial transactions and offers broker-dealer services. Brokers, banks and exchanges use its systems to buy and sell stocks and derivatives, obtain price quotes, and manage trade orders.

Overall, this transaction seems to represent a furthering of NYSE's ambition to become a more important source of transaction infrastructure, beyond just providing marketplaces and related market data, in a fairly evolutionary way, Fox-Pitt analysts said in a research note.

The acquisition will be done through NYSE Technologies, an indirect, wholly owned subsidiary of NYSE Euronext.

The boards of NYSE Euronext, NYSE Technologies and NYFIX have approved the acquisition, which is also subject to approval by NYFIX shareholders and regulators.

The transaction is expected to close in the fourth quarter of 2009 and add to NYSE Euronext 2010 earnings, excluding one-time deal and restructuring costs.

NYSE Euronext shares fell 1.8 percent to $28.26 on the New York Stock Exchange. NYFIX shares rose 77 cents to $1.63 in Nasdaq trading. (Reporting by Juan Lagorio, editing by Maureen Bavdek and Derek Caney)