Telefonica on Monday officially told labour union representatives that it intends to cut jobs in Spain, the UGT union said.
The telecoms company did not indicate how many jobs it intends to cut, the union said in a statement on its website.
Spanish newspaper Expansion said the company wants to reduce its 21,000-worker payroll by 2,500, while rival newspaper Cinco Dias said the company may cut as many as 3,000 jobs.
A spokesperson for Telefonica declined to comment.
The cuts are part of the company's three-year strategic plan to boost profitability by reducing capital expenditure, raising revenue and cutting costs.
(Reporting by Matteo Allievi, editing by Inti Landauro, Kirsten Donovan)