As a growing online advertising market is propelling some online media toward making free content available to attract eyeballs - and ad dollars - the New York Times announced yesterday that it will introduce a fee-based subscription service for some its most popular content online. Called TimesSelect, the new service will cost $49.95 a year, and provide access to Times and International Herald Tribune columnists and the Times online archives.

The service is scheduled for launch in September and will be free for home-delivery subscribers. Most material on the Times website, NYTimes.com, will remain free. Articles are free for seven days after publication; a fee is charged once they are archived.

Though advertising on websites accounts for only 2-3 percent most newspapers' revenues, it is the fastest-growing source of income. According to the Times, in April its website had 1.7 million unique visitors daily; its newspaper circulation in March was 1.1 million. Yet, many newspaper websites are loath to charge for content, fearing that readers would flock to free sites, taking advertisers with them.