The Economist Group — which includes information providers the Economist Intelligence Unit and CQ Roll Call — had operating profits of £60m last year, compared with the FT Group's £24m.
The potential buyers include families such as the Schroders, the Cadburys, and Rothschilds, one person close to the situation said. A deal is not imminent, but is expected to be agreed over the summer, the person added.
John Elkann, scion of the billionaire Agnelli family, is also a major shareholder. Fiat, the carmaker controlled by the Agnellis, is the biggest shareholder in RCS Mediagroup, publisher of Italian newspaper Corriere della Serra.
Any deal would have to be approved by the four trustees of the Economist Group, including former Conservative minister Lady Bottomley and former Cabinet secretary Lord O'Donnell.
The trustees' role is to preserve "the continued independence of the ownership of the company and the editorial independence of the Economist".
Pearson declined to comment.
Media groups Bloomberg, Thomson Reuters and Axel Springer. were also approached about the stake, two person close to the situation said. But those companies declined to pursue an acquisition, because owning it would not give them control of the group, the person said.
Pearson acquired half of the Economist in 1957, as part of its acquisition of the Financial Times. But its stake, constituted of B shares, entitle it to name only six of the 13 members of the group's board.
The majority of the board are named by the holders of the A shares — families including the Cadburys, Rothschilds and Schroders, as well as some current and former employees. The Economist's editorial independence is safeguarded by the fact that the trustees must approve any transfer of A or B shares, and the appointment of each new editor.
In recent years the Economist Group has been seeking to diversify away from sales of print advertising, which fell 18 per cent in 2014, by launching a foreign-language edition and a new video venture.
In January the Economist appointed Zanny Minton Beddoes as its first female editor in its 172-year history, succeeding John Micklethwait who joined Bloomberg News as editor-in-chief.
Unlike the Financial Times, the magazine's editorial independence is formally enshrined in its corporate set-up.
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So strong is the magazine's editorial department that, while most of the group has moved to Canary Wharf, it has remained in its offices in Mayfair.
Managers have now all but given up on the journalists joining them in the Docklands, with one alternative to relocate the whole company somewhere else, a senior employee at the Economist Group said.
Selling the FT Group and the Economist Group stake would leave Pearson with nearly £1bn in net proceeds — strengthening its balance sheet at a time when its credit rating has a negative outlook from Moody's, due to uncertainty in the education sector.
Pearson's chief executive John Fallon has pledged to prioritise investments in the company's existing education business ahead of pursuing further acquisitions. He has also underlined Pearson's reluctance to return cash to shareholders through buybacks or special dividends, although the company does have a policy of increasing dividends faster than the rate of inflation.