Taking a new hard line that news articles should not turn up on search engines and Web sites without permission, The Associated Press said Thursday that it would add software to each article that shows what limits apply to the rights to use it, and that notifies The A.P. about how the article is used.

Tom Curley, The A.P.’s president and chief executive, said the company’s position was that even minimal use of a news article online required a licensing agreement with the news organization that produced it. In an interview, he specifically cited references that include a headline and a link to an article, a standard practice of search engines like Google, Bing and Yahoo, news aggregators and blogs.

Asked if that stance went further than The A.P. had gone before, he said, “That’s right.” The company envisions a campaign that goes far beyond The A.P., a nonprofit corporation. It wants the 1,400 American newspapers that own the company to join the effort and use its software.

“If someone can build multibillion-dollar businesses out of keywords, we can build multihundred-million businesses out of headlines, and we’re going to do that,” Mr. Curley said. The goal, he said, was not to have less use of the news articles, but to be paid for any use.