A private placement memorandum and proxy materials outlining the restructuring of the National Association of Securities Dealers and Nasdaq “in substantive detail” will be sent to NASD members “in the coming weeks,” the NASD said Feb. 4.

Specific details emerged with the release of an unusual electronic joint letter that was sent to NASD members by NASD Chairman Frank Zarb and Alan Davidson, an NASD board member who also is president of the Independent Broker-Dealer Association and head of the Long Island-based Zeus Securities Inc. brokerage firm.