ENTERTAINMENT

New TV Ratings Service Planned: Arbitron Co. said it would introduce a high-tech TV ratings service that would measure both viewing levels and product purchases among 1,000 households. The venture is designed to attack A. C. Nielsen Co.’s long-held monopoly on the national TV ratings business. Building upon its ScanAmerica product purchase tracking system already in place, Arbitron said the initial five-city rollout in New York, Los Angeles, Chicago, Atlanta and Dallas includes clients CBS, ad agency Young & Rubicam and Bristol-Myers Squibb.