Knight Ridder expects strong ad sales to continue in the second half and is "comfortable" with full year earnings estimates of $3.65 to $3.70 a share, exceeding the consensus estimate of $3.64. The No. 2 U.S. newspaper publisher said ad sales were up 5.8% in April and that May would be "even stronger." Internet unit KnightRidder.com forecast year 2000 sales of $50 million and expenses of $90 million to $100 million with break even possible in 2002. In trading Friday, Knight Ridder closed at $51.25, up 2.50% for the week.