The New York Times will start charging for full access to its website as it takes another stab at getting readers to pay for news.

Readers who do not subscribe to New York Times Co's namesake newspaper will able to read 20 articles per month on the website for free, but will have to pay to read more.

Subscribers to the print edition will have full, free access to the website,

The newspaper launched the pay model in Canada on Thursday and will roll it out in the United States and globally on March 28.

The pay model is a big test for large-circulation general interest newspapers, which have struggled to retain readers and advertisers as more and more people get their news from the Internet.

The scheme is being closely monitored by other news organizations weighing similar plans.

The Times' strategy is similar to that of the Financial Times, which has had some success charging high-end business readers for online access.

The Wall Street Journal, once a newspaper targeted to financial professionals, has also successfully charged, even as it has broadened out to become more of a general newspaper under News Corporation's Rupert Murdoch. The Journal is now the largest U.S. newspaper.

This is the second attempt by the New York Times, one of the world's most prestigious papers, to charge for digital news in hopes of diversify its revenue stream.

It will charge $15 per month for unlimited access to and a smartphone application; $20 per month for online access and an Apple Inc iPad app; and $35 per month for online, smartphone and an iPad app.

The New York Times said it will begin using Apple's new subscription service in its app store by June 30.

Readers who come to Times articles from other sources such as blogs and social media sites including Facebook will be able to access content even if they hit the limit. However, the Times is limiting the amount of free articles on Google to five a day.

Today marks a significant transition for The Times, an important day in our 159-year history of evolution and reinvention, New York Times Chairman and Publisher Arthur Sulzberger Jr. said in a statement.

The newspaper attempted to get readers to pay in 2005, charging non-print subscribers for online access to columnists such as Frank Rich, Maureen Dowd and Thomas Friedman. The scheme was dropped after two years in the interests of attracting more readers to its website.

In January 2010 the New York Times said it would try again with a metered pay system inspired by sites as varied as those of Pearson Plc's Financial Times, Consumer Reports and WeightWatchers.

Devising and implementing the system took 14 months.

The new pay model allows causal readers to access the New York Times, unlike some other pay strategies employed by other news organizations, such as News Corp's experiment with the Times of London. The British paper bars anyone who does not pay from reading its website, an action that has resulted in a 90 percent plunge in visitors.

About 31.4 million individuals visited in February, according to online research measurement firm comScore.

It remains to be seen whether people will pay for digital news. Of the three dozen newspapers that have moved to some sort of online pay model, only 1 percent of readers have opted to pay, according to a recent study by the Pew Research Center's Project for Excellence in Journalism.

New York Times Co shares were up 9 cents at $8.95 in afternoon trading.

(Editing by Lisa Von Ahn, Gerald E. McCormick and John Wallace)