Irvine-based call center operator Alorica Inc. bought Expert Global Solutions in Plano, Texas, on undisclosed terms.

Both companies run call centers and are about the same size, each with 40,000 to 50,000 employees and revenue of more than $1.1 billion.

The combined company will operate under the Alorica name, have revenue of $2.3 billion, employ 52,000 in North America and about 38,000 overseas, and provide services in 30 languages to more than 600 clients in a dozen countries.

Alorica is the fifteenth-largest private company in Orange County.