Mexican billionaire Carlos Slim has purchased a minority stake in British telecommunications giant BT, the group announced.
Slim, one of the world's richest people, has taken a holding worth about £400 million ($511 million) via family-controlled companies, BT said in a statement issued late Wednesday.
Slim becomes the latest high-profile investor after French-Israeli billionaire Patrick Drahi, who is BT's biggest shareholder with a holding of almost 25 percent.
In reaction to the news, BT's share price gained 3.8 percent to 134.30 pence in late Thursday afternoon deals on London's falling stock market.
"News that... Slim has built a 3.0-percent stake in BT is making a splash through the markets," said Sophie Lund-Yates, lead equity analyst at UK stockbroker Hargreaves Lansdown.
"On its own, the investment doesn't mean too much, but it potentially opens the door to some interesting developments down the line."
Stocks had rallied in mid-May after BT ramped up its shareholder dividend, extended a major cost-cutting drive and posted a bright outlook, offsetting news of tumbling annual profits.
BT is in the process of axing up to 55,000 jobs, or 42 percent of its workforce, by the end of the decade amid a tech jobs cull in response to rampant inflation.