Taking cues from Securitiesand Exchange Commission Chairman Arthur Levitt, the leaders of the NationalAssociation of Securities Dealers and the New York Stock Exchange havelaid out different proposals to safeguard their regulatory units.

Facing off at a Tuesday hearingbefore the U.S. Senate Committee on Banking, Housing and Urban Affairs,Frank Zarb, chairman and chief executive officer of NASD, which owns theNasdaq Stock Market, and NYSE Chairman and CEO Richard Grasso spelled outplans to demutualize their non-profit stock markets by converting theminto for-profit, publicly traded institutions.