By LOIS WEISS

September 7, 2005 -- THE end of summer didn't mean a minute's pause for real estate execs.

A portfolio of close to 3,000 units was transferred last week to a joint venture of Joel Weiner's Pinnacle Group and the Praedium Fund for $500 million. Sources tell us seller Baruch Singer hired broker Georgia J. Malone to quietly handle the off-market deal, which included Singer's participation in the buying entity. It was so quiet, no one ever reported the package of 104 Harlem and Upper West Side buildings as even being on the market. Lehman Bros. handled the financing...