Former Sotheby's auction house chairman Alfred Taubman was found guilty in a US District Court yesterday of conspiring to fix prices with rival Christie's in a multimillion dollar scandal that shook the art world. The jury deliberated for less than two days to decide if Taubman, 76, masterminded a deal with his Christie's counterpart Anthony Tennant in the 1990s to fix commissions that allegedly bilked art sellers out of millions of dollars.