Newsweek, the 80-year-old US current affairs magazine, is to become an online-only publication.

The last print edition will be on 31 December, reflecting the trend for newspapers and magazines to move online as traditional advertising declines.

Newsweek merged with the internet news group the Daily Beast two years ago.

The Daily Beast’s founder, Tina Brown, said its site now had more than 15 million unique visitors a month, a 70% increase on last year.

Tina Brown said in a statement: “Exiting print is an extremely difficult moment for all of us who love the romance of print and the unique weekly camaraderie of those hectic hours before the close on Friday night.

“But as we head for the 80th anniversary of Newsweek next year, we must sustain the journalism that gives the magazine its purpose – and embrace the all-digital future.

“This decision is now about the quality of the brand or the journalism – that is as powerful as ever. It is about the challenging economics of print publishing and distribution.”

Newsweek is to become an online-only publication

Newsweek rose to become the second largest US news weekly magazine, behind Time. But declining circulation and advertising saw it fall into losses.

It was sold by the Washington Post Company to Sidney Harman in August 2010, and was merged with the Daily Beast three months later.

Tina Brown, who became Lady Evans when her husband Harold Evans, the legendary journalist, was knighted, is a former editor of Vanity Fair and The New Yorker.

She teamed up with Barry Diller to launch The Daily Beast in 2008. The website’s name comes from the fictional newspaper in Evelyn Waugh’s 1938 novel Scoop.