They are speaking about a merger, one of the people, a senior financial source familiar with Deutsche Boerse, said on Wednesday.
Deutsche Boerse and NYSE Euronext both declined to comment.
Trading in Deutsche Boerse shares was halted on Wednesday after speculation of a potential merger deal between the two was pending.
Speculation was fueled by the announcement that London Stock Exchange
NYSE Euronext has market value of about $9 billion, smaller than Deutsche Boerse's 11 billion euros ($15 billion).
(Reporting by Edward Taylor, Philipp Halstrick, Arno Schuetze, Harro ten Wolde and Ludwig Burger; Editing by Will Waterman)