* No firm date set for board to consider counterbid-source
* Nasdaq's $11.3 bln offer meant to trump Deutsche Boerse (Adds more background on bid, process; byline)
By Jonathan Spicer
NEW YORK, April 5 (Reuters) - NYSE Euronext's board of directors plans to meet by April 14 to consider Nasdaq OMX Group's unsolicited takeover bid, though no firm date has been set, a person familiar with the plan said on Tuesday.
On Friday, Nasdaq partnered with U.S.-based IntercontinentalExchange Inc to make an $11.3 billion offer for the Big Board parent, an attempt to thwart a friendly $10.2 billion takeover offer from Germany's Deutsche Boerse.
The counterbid would bring together fierce U.S. rivals Nasdaq and NYSE and hand the target company's profitable derivatives business to ICE, revamping ownership of the world's capital markets as a merger frenzy takes hold.
NYSE's board has a few main options: determine Nasdaq's bid is "superior" to that of Deutsche Boerse; reject it as inferior; or request more information from Nasdaq and ICE.
The 16 board directors will likely weigh the amount offered, as well as any regulatory and other risks, in determining whether the bid is better for shareholders.
The source requested anonymity because of the sensitivity of the matter.
NYSE Euronext said on Friday its board would "carefully review" the new offer and urged shareholders not to take any action pending its review. Deutsche Boerse will wait until the NYSE board responds before considering raising its offer, separate sources said on Monday.
NYSE Euronext shares are up 10.7 percent since the new bid was announced, and were mostly flat at $38.95 on Tuesday. Nasdaq shares are up 8.4 percent since it unveiled the bid, while ICE has slipped 3.7 percent.
There is a relatively steep 250 million euro ($355 million) termination fee attached to the Deutsche Boerse-NYSE Euronext plan, unveiled in February, which would create the world's top exchange operator co-headquartered in Frankfurt and New York.
The offer from Nasdaq and ICE is a complicated cash-and-stock transaction that was pitched with an appeal to U.S. patriotism, though it would face U.S. antitrust hurdles.
Exchanges globally are planning tie-ups, including London Stock Exchange's offer for Canada's TMX Group Inc. On Tuesday, however, Australia's government said it intends to reject Singapore Exchange Ltd's bid for ASX Ltd, underscoring the difficulties of merging national exchanges. (Reporting by Jonathan Spicer, editing by Gerald E. McCormick and Maureen Bavdek)