"The agreement signed with UNI will bring a complementary framework to further enhance our practices for the benefit of all our employees", Chairman and CEO Daniel Julien said in a statement.

Teleperformance's shares slumped in November on news of an investigation into harsh working conditions in Colombia.

The pact covers the company's 440,000 employees worldwide and its implementation will begin in the coming weeks, with an initial focus on Colombia, Poland, Jamaica, El Salvador and Romania, the group said.

(Reporting by Diana Mandiá;Editing by Elaine Hardcastle)