MADRID (Reuters) – Spanish telecom giant Telefonica will offer its employees the opportunity to work a four-day week, extending a pilot programme that has involved around 150 workers so far, three sources familiar with the matter said on Wednesday. In exchange for a 12% pay cut, the deal would let staff work four days, or 32 hours, a week instead of 37.5 hours now, on a voluntary basis, a union source said. The pilot project was launched in 2021 as part of wider negotiations with unions in the aftermath of the coronavirus pandemic, and will now be available to around 17,000 employees from Sept…