MADRID (Reuters) – Short-term accommodation in Spain’s 20 biggest cities is rapidly catching up with the number of rooms managed by hotels, a study released on Tuesday found, prompting hoteliers to call for better regulation of their upstart rivals. Spanish travel industry association Exceltur said that about 300,000 homes are offered for short-term rental in the country’s 20 largest cities, with some 389,779 rooms managed by hotels. Exceltur, which groups together major Spanish hotel chains, travel agents, tour operators and airlines, is lobbying for a new law to regulate short-term rental pl…