MADRID, July 29 (Reuters) - Orange"s (ORAN.PA) Spanish unit will invest nearly 4 billion euros ($4.75 billion) in 2021, its chief executive said on Thursday, almost quadrupling the previous year"s commitment despite bruising markets and a 3.7 billion-euro writedown in the second quarter. France"s biggest telecom firm announced the impairment on the value of its Spanish activities earlier on Thursday, saying it reflected competition that has hurt sales and profits in its second-largest market. read more "The Spanish market is hyper-competitive... but amid the three main operators Orange is a strong second," CEO Jean-Francois Fallacher told reporters in a call. The impairment on the value of its Spanish activities will not impact strategic priorities, ability to invest or cash flow, Fallacher said, highlighting last week"s 350 million euro investment in two bands of the 700 megahertz spectrum auction vital to 5G deployment. "We are full speed with our investments in the Spanish market," Fallacher noted. Spain doubled the length of spectrum concessions to 40 years this year and removed the tax telecos used to pay national broadcaster RTVE, which Fallacher said had weighed on operators and hindered them from focusing on the 5G rollout. Another obstacle has been football"s prohibitively priced viewing rights. Fallacher called for the regulator-determined formula to pro-rate the number of football customers rather than the number of paid television customers. "The formula to calculate prices is so perverse that even if Orange Spain gains football customers, they are totally irrelevant in the cost computing," the teleco"s consumer division vice president Diego Martinez told reporters. Spain has been a headache for Orange over recent quarters, prompting it to oust its local boss and lay off 485 people in the country but restructuring will allow new skills to be recruited for the future, Fallacher said. read more Orange Spain is ready to renegotiate contracts giving Euskaltel (EKTL.MC) third-party access to its network services should an expected merger with Masmovil go through. However, Fallacher said third-party operators accessing network services through leasing contracts were damaging margins. "We like competition, but will be able to invest less and less if this trend continues," he warned. ($1 = 0.8423 euros)