Nov 22 (Reuters) - Britain"s competition regulator is examining whether British Airways owner IAG"s (ICAG.L) planned 500 million euro ($563.2 million) purchase of Spain"s Air Europa would harm competition in the UK, the watchdog said on Monday. IAG had announced its plans to buy Air Europa for 1 billion euros in 2019, but the price was cut in half this year after the airline industry was sent into a tailspin by the COVID-19 pandemic. read more The British company has already offered concessions to address EU antitrust concerns over the deal, a filing showed last month, though details were not provided. The European Commission opened an in-depth investigation in June, voicing concerns that the proposed transaction would reduce competition on Spanish domestic routes and on international routes to and from Spain. The deal, which involves Iberia buying Air Europa on behalf of IAG, had sparked opposition from the Unite union over jobs and from rival carriers. The Competition and Markets Authority (CMA) said it has a Jan. 19 deadline for its initial investigation decision. "We will collaborate with the CMA. The London-Madrid route is highly competitive and is already part of the European Commission (investigation) process," IAG said on Monday. ($1 = 0.8878 euros) Reporting by Yadarisa Shabong in Bengaluru Editing by David Goodman