Carlos Slim, once the world's richest man, has increased his stake in UK telco giant BT to 4.3 percent via his family investment firm.
The Mexican tycoon initially acquired a 3.2 percent stake in BT in June.
In a brief regulatory filing today, BT noted the 1.1 percent stake increase.
It builds on the stake Slim acquired in June, worth £400 million ($525m), through financial holding company Inbursa and its subsidiaries, which are controlled by the family of the businessman.
Slim built his fortune via a 1990s concession for Mexico’s state telephone company.
His group controls América Móvil, and has also previously acquired stakes in European telecoms groups KPN and Telekom Austria.
Last month, Indian conglomerate Bharti Global agreed to acquire Altice's 24.5 percent stake in UK telco giant BT, the largest stakeholder in the company.
Patrick Drahi only increased Altice UK's stake in BT to 24.5 percent in May of last year, and even had plans to increase it to nearly 30 percent. However, after years of acquisitions, the company has been looking to shift assets in order to pay down its mounting debt, which sits at around $60bn.