Eugene, Ore.--Tech ad pages continued their decline in the first half of 1999, although the slide showed signs of leveling off, according to figures released by Adscope, a tracking service. In the 445 publications tracked by Adscope, which range from USA Today to Computer Reseller News, ad pages fell 9% to 125,292 in the first six months of 1999 compared with the same period last year. Ad expenditures dipped 3% to $1.7 billion in the first half of 1999 compared with the same period last year. The decline seems to have slowed, considering ad pages declined 15% and ad revenue declined 6% between the first quarter of 1998 and the first quarter of 1999. Each of the top five technology publishing houses showed a decline in ad pages. Ziff-Davis fared the worst, with its pages falling to 12,992 in the first half of 1999, a 21.49% change from the same period last year. International Data Group fared better. Its ad pages fell to 9,816 in the first six months of 1999, a 3.99% decline.