Japan's Nikkei has agreed to buy the FT Group, publisher of the Financial Times newspaper, from Britain's Pearson for 844 million pounds ($1.31 billion) in cash, the two companies said on Thursday.The deal did not include the FT Group's 50 percent stake in The Economist magazine. Pearson said the FT Group contributed 334 million pounds of sales and 24 million pounds of adjusted operating income in 2014.Nikkei describes itself as the largest independent business media group in Asia.