New York--Reflecting the continuing weakness in the advertising market, total magazine ad pages declined 16.9% in May compared with May 2000, according to the Publishers Information Bureau. The double-digit downturn in ad pages followed declines of 9.5% in April and 8.1% in May, bringing the year-to-date falloff to 9.4%. Business publications focusing on the new economy continue to get hit the hardest. Ad pages for Business 2.0, which was sold to Time Inc. late last week for $68 million, were down 49% while Red Herring's ad pages were down 44%. The A-list books in the business category also took it on the chin in May, with Business Week down 35% in ad pages and Fortune off 32%.