The Washington Post said Monday it would start charging frequent readers for online access starting in mid-2013, with some details still to be finalized.
The move, which had been expected, will require a paid subscription after 20 articles or multimedia features have been read per month, the Washington Post Co. said in a statement.
The Post's homepage, section front pages and classifieds will not be limited, the statement said.
The company said an exact launch date had not been decided, nor had the subscription price.
It said home delivery subscribers will have free access to all Post digital products and that students, teachers, school administrators, government employees and military personnel would also have unlimited access "while in their schools and workplaces."
The Post had been one of the last top US newspapers to offer its content free of charge online, but has been facing financial struggles along with the rest of the industry.
"News consumers are savvy; they understand the high cost of a top quality newsgathering operation and the importance of maintaining the kind of in-depth reporting for which The Post is known," said publisher Katharine Weymouth.
"Our digital package is a valuable one and we are going to ask our readers to pay for it and help support our newsgathering as they have done for many years with the print edition."
She added that the paywall "will allow us to stay connected to the people who visit periodically or find us through search and social networks and it gives us an additional revenue stream to support the great work of our newsroom."
The newspaper said links to Post articles through Google, Facebook or other searched or shared links will not be subject to the paywall limits.
A study released Monday by the Pew Research Center said the US newspaper industry is seeing some glimmers of hope after being battered for years.
While the industry is about half the size it once was, there are some positive signs, including new revenue streams from digital paywalls and a general economic improvement which is aiding newspapers, the study found.
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