New York Times Co. said it will begin charging readers who don’t subscribe to its namesake newspaper on Mar. 28 for content on the publication’s website. The company’s stock rose.

The company will charge $15 every four weeks for unlimited access to the site from a computer or mobile phone, the company said in a statement. A package for access online and through the paper’s tablet-computer application will run $20 every four weeks and access from any device will be $35.

Times Co. is looking to its website to bolster revenue as print advertising and circulation sales fall. The company’s revenue slid 1.9 percent last year to $2.39 billion, the fourth year of decline.

Non-subscribers will still be allowed to read 20 stories for free each month, and access the home page and section fronts.

Readers who find links to stories from some search engines and blogs will also be able to read those stories for free, even if they’ve reached the limit.