NYSE Euronext sees cost savings in its $9.8 billion deal with Deutsche Boerse at closer to 400 million euros ($583 million), up by about a third from its initial estimate, according to a Big Board spokesman on Sunday.

NYSE Chief Executive Duncan Niederauer also sees the biggest NYSE and Deutsche Boerse customers saving at least $3 billion from the combination of their European derivatives platforms, according to spokesman Richard Adamonis.

Adamonis was confirming comments made earlier by Niederauer in an interview with the Financial Times.

The new savings estimate, along with a 100 million euros in benefits coming from cross-selling and distribution opportunities, would bring the total savings and benefits from the deal to about $725 million, closer to the estimates from a competing takeover offer.

Nasdaq OMX Group Inc and IntercontinentalExchange Inc have launched a rival $11.2 billion takeover bid for NYSE Euronext. That deal promises net savings and benefits, or synergies, of $740 million.

Last week, NYSE's board rejected the Nasdaq/ICE bid for the second time in 11 days.

JOB CUTS

U.S. Sen. Charles Schumer of New York was expected to ask Nasdaq and ICE about potential job losses if they succeeded in their bid, the Wall Street Journal reported on Sunday.

In a letter expected to be sent Monday, Schumer cited estimates by NYSE that a merger with Nasdaq could cost 1,000 U.S. jobs, or about a third of the U.S.-based employees of the combined company, the Journal reported.

The estimates are based on NYSE's research from about 12 to 18 months ago when it looked at buying Nasdaq, the paper reported, citing an unnamed source.

Earlier this month, Schumer said he was concerned about the impact of the bid on jobs in New York.

A spokesman for Schumer could not be reached immediately for comment late on Sunday.

The U.S. lawmaker is one of the key political figures whose support could be crucial for any deal involving NYSE, the iconic exchange whose takeover can take on a populist hue.

Pride and nationalism around domestic exchanges have scuttled such deals in the past. Earlier this month, the Australian government blocked Singapore Exchange Ltd's $8 billion bid for ASX Ltd, saying changes to the country's financial systems were needed before foreigners could buy the bourse.

In their bid, Nasdaq and ICE are hoping some of these fears work to their advantage over the German exchange. They have appealed heavily to the United States' thirst for remaining the world's financial center, its anxiety about losing out on new listings and its need for a more stable market.

SHAREHOLDER VOTES

All four exchanges involved in the increasingly bitter takeover battle are trying to persuade NYSE shareholders to back their deal.

Niederauer's comments come ahead of a closely watched NYSE shareholder meeting on April 28 for their annual vote on the company's directors.

Analysts have said that vote could be an early sign of how shareholders feel about the NYSE board's decision to back the Deutsche Boerse over the rival, higher bid.

The vote on the Deutsche Boerse deal is expected on July 7, according to Niederauer's comments and confirmed by his spokesman.

(Reporting by Paritosh Bansal, editing by Bernard Orr and Matt Driskill)