ATLANTA — The top executive of IntercontinentalExchange Inc. said Wednesday his company has more ammunition if the combat for ownership of NYSE Euronext requires ICE and its partner Nasdaq OMX Group Inc. to improve the terms of their offer for the stock exchange giant.

ICE CEO Jeff Sprecher also predicted that shareholders of NYSE Euronext would reject the company’s proposed deal with Deutsche Boerse if a vote were held now, citing investor frustration with the NYSE board’s refusal to engage ICE and Nasdaq.

“We have maintained a lot of flexibility around our deal as well,” said Sprecher, speaking on a conference call detailing ICE’s first-quarter earnings.

Sprecher said in an interview that he and Nasdaq CEO Bob Greifeld see no current need to change terms of their deal, which values NYSE Euronext at about $11 billion, but “we have flexibility if our shareholders and the NYSE shareholders think that there’s a better form of giving our purchase price.”

NYSE is “rushing” a July 7 vote on the Deutsche Boerse merger while providing investors with little certainty that it can pass muster with European antitrust authorities, according to Sprecher.

ICE aims to carve out NYSE Euronext’s London- and Europe-based derivatives businesses with Nasdaq OMX taking ownership of its equity and technology divisions. NYSE has so far favored its agreed deal to combine with Deutsche Boerse.