The deal did not include the FT Group's 50 per cent stake in The Economist magazine
The sale of the FT Group does not include its 50 per cent stake in The Economist magazine or the London headquarters of the newspaper on the banks of the River Thames.
Reuters reported earlier on Thursday that the 171-year-old Pearson had finally decided to sell the pink-paged business daily after years of speculation that it could be sold as Pearson expanded into education.
That report prompted a flurry of speculation, with two newspapers including the Financial Times reporting that Germany's Axel Springer would be the buyer, which Springer subsequently denied.
In a joint statement, Pearson said it had agreed to sell the FT Group to Nikkei for $1.3 billion in cash.
"I am extremely proud of teaming up with the Financial Times, one of the most prestigious news organisations in the world," said Tsuneo Kita, cairman and group CEO of Nikkei. "We share the same journalistic values."
Trophy assets
While the FT has done a better job than most in adapting to the digital revolution, helped by a loyal customer base who will pay for access to the newspaper and website, analysts are not convinced it makes much of a profit.
Pearson does not break out the financial details of the newspapers.
"They've done a good job - probably better than anybody else from a UK newspaper perspective - in terms of transitioning to a model online, so I think you can see why that is attractive," said one analyst, who asked not to be named.
Full-year results for 2014 showed the FT increased its circulation by 10 percent to a record high of nearly 720,000 in print and online. More than 500,000 were digital subscriptions, representing 70 percent of the FT's total paying readers.
Pearson, founded in 1844 as a small building firm in Yorkshire, northern England, was once one of the world's largest building contractors and has had a long list of varied interests from banking and publishing to owning theme parks and Madame Tussaud's waxworks.
It bought the FT in 1957.
The group though has moved to focus solely on education and has sold off other news interests such as Mergermarket Group and a company which included French business newspaper Les Echos in recent years. In 2012 it merged its Penguin book division with Random House.
It has endured a tough time of late, with weaker demand in the North American education arm. Analyst Ian Whittaker said Pearson would likely use any proceeds to pay down debt.
"If they could obtain a trophy asset price then it could look pretty good against the relatively modest profits that the FT generates," said Richard Marwood, senior fund manager at AXA Investment Managers, a shareholder in Pearson.
Additional reporting by Paul Sandle, Sarah Young and Neil Maidment in London, Jennifer Saba in New York, Klaus Lauer and Erik Kirschbaum.