Dealer Who Sold Portrait Joins Leonardo Debate.

An American dealer who in 1998 bought -- and later sold -- a mixed-media portrait of a young woman that some art and scientific experts now attribute to Leonardo da Vinci has come forward to say that she does not think it is by that Renaissance master. ''Even though I honestly do not know what this drawing is, I still believe that it is not a Leonardo,'' said Kate Ganz, the Manhattan dealer who bought the work, which was labeled a 19th-century German School portrait, at auction at Christie's in New York for $21,850. She later sold it in January 2007 for the same price, less a dealer's discount to the buyer, she said. [ABSTRACT FROM PUBLISHER]