Mr. Wille, 48, will be responsible for various elements of NYSE Hybrid Market development, and will report to Louis G. Pastina, senior vice president of Market Development and product manager for the Hybrid Market.

"Mark brings a unique blend of experiences back to the NYSE and will be instrumental in helping the Exchange develop the NYSE Hybrid Market, a mission-critical initiative to enhance our value to customers," Mr. Pastina said.

The NYSE Hybrid Market, to be introduced in phases through second-quarter 2006, will integrate into one platform the best aspects of both the auction market and automatic trading. It will give NYSE customers a broader array of trading choices than any other market, expanding their ability to trade instantaneously, with certainty and anonymity, while maintaining the market quality that investors have come to expect from the NYSE.

Prior to joining the NYSE, Mr. Wille was the head of Product and Project Management with International Securities Exchange. From 2000 to 2002, he was with Knight Trading Group, most recently as vice president, Trading Systems. Mr. Wille was previously employed by the NYSE as managing director, Specialist Trading Systems and Capacity Planning from 1987 to 2000. He transferred to the NYSE from Securities Industry Automation Corp., the NYSE's systems provider and subsidiary, where he was a manager from 1985 to 1987. Mr. Wille has a Master’s in Interactive Telecommunications from New York University and a Bachelor’s in Modern Languages from Kansas State University.