More than 10,000 overseas contractors are working for Telstra at the same time as the company slashes jobs at home to help boost profit.

This represents about 26 per cent of the telco's full-time workforce of 38,000, underscoring the extent of an aggressive outsourcing program to tap staff in low-cost countries.

Telstra has defended trimming its domestic workforce, saying offshoring call centre jobs are necessary to give the company flexibility. Credit:Arsineh Houspian

Telstra has made 3157 jobs redundant since the beginning of the year - eclipsing the combined Australian manufacturing workforce of car makers Holden and Ford. Last month Telstra outlined details to shed 1100 jobs as part of a national restructure, sparking an outcry by unions.

Among jobs cut are 1100 from its operational department, 605 from its business directories business and another 1552 across the company, including staff in customer services, figures compiled by the Community and Public Sector Union show.