BT is buying Singapore-based IT services and consulting firm Frontline Technologies for $202m(£98.9m).
BT said in a statement that the takeover complemented its existing Asian operations and would broaden the kind of solutions it can offer in the region.
Three executive directors of Frontline will keep their existing roles. Shareholders representing 41 per cent of total share capital have given undertakings to support the takeover.
In a separate announcement Frontline announced it has agreed to buy nine per cent of Indian infrastructure firm Accel Frontline Limited - Frontline already owns 41 per cent of the firm.
Frontline was set up in 1993 and has 3, 900 staff in China, Hong Kong, India, Indonesia, Malaysia, Singapore, the Philippines, Taiwan and Thailand. Turnover for the most recent financial year, ended 31 March 2007, was $200.5m(£98.2m) and net profit was $9.55m(£4.6m). It is listed on the Singapore exchange, shares were suspended earlier this month pending the announcement.
BT's statement to the Stock Exchange is here.