Customer services provider Convergys said it would buy rival Stream Global Services from Ayala for $820m (£498m).
Convergys said the buyout of the business process outsourcing firm would boost its client base, service capabilities and its presence internationally.
Convergys president and CEO Andrea Ayers said:"Both Convergys and Stream have a history of commitment to our clients, and dedication to excellence in representing the world's largest brands."
"We expect this transaction to be highly accretive and to allow us to leverage our strong balance sheet to position Convergys for enhanced revenue, margin improvement and EPS growth."
Upon the completion of the deal in Q1 this year, Convergys will have about 125,000 employees.
Ayers added: "We believe this combination will strengthen Convergys by diversifying our client base and enabling us to offer a wider range of customer transactions in a more cost effective manner from multiple geographies, at scale.
"Our plan is to build upon the best practices and management teams from both companies to deliver superior customer benefits and enhanced value for our clients and shareholders, and provide new opportunities for our employees."
Stream, which has over 40,000 employees, offers customer relationship management (CRM) services in 22 countries.