NEW YORK — A year after it began charging for full access to its website, The New York Times is cutting the number of articles available for free from 20 per month to 10.

The change, which takes effect in April, will affect “a relatively small number of people,” said Times spokeswoman Eileen Murphy.

The Times offers three unlimited access plans, ranging in price from $15 per month to $35. Each plan has an introductory price of 99 cents for the first four weeks. Print subscribers get online access for free.

The company says it has 454,000 digital subscribers to The New York Times and the International Herald Tribune, which began imposing similar charges in October. The company didn’t break out figures, but the vast majority was for the Times as of the end of 2011. By comparison, the newspaper had roughly 790,000 print subscribers for the six-month period ending Sept. 30, according to the Audit Bureau of Circulations.

The website’s “paywall” has many gaps. Readers who follow links in emails, on Web pages, on Facebook or on Twitter can access individual articles for free even after they reach their limit.

Those cracks in the paywall have allowed the newspaper to keep most of its online readership. The number of U.S. visitors fell just 2 percent to 31 million in February compared with a year ago, according to tracking firm comScore.

Charging readers for unlimited online access has helped boost the Times’ circulation revenue. But the effort hasn’t generated enough to offset a decline in advertising revenue.

In the last three months of 2011, digital and print circulation revenue grew 5 percent to $242 million, while companywide ad revenue fell 7 percent to $359 million, the company said. Overall revenue fell 3 percent.

Evercore analyst Douglas Arthur said the newspaper’s announcement showed its confidence in the online subscription model. He said it was “the first good news” for the company in some time. Arthur has an “overweight” rating on Times Co. stock with a $9 price target.

The New York Times Co.’s stock increased 5 cents to close Tuesday at $6.92.

The Times’ success has inspired other U.S. newspaper publishers to impose similar restrictions.

Last month, Gannett Co. Inc. said it would start charging readers for online access in all of its 80 local newspaper markets by the end of the year. Under Gannett’s plan, non-subscribers will have free access to five to 15 articles a month.

Tribune Co.’s Los Angeles Times began charging for online access this month. It allows non-subscribers to read 15 stories a month for free.