The series 440 consists of a total of 255 multiple units which were introduced after the RENFE electrification had been switched from 1,500 to 3,000 Volts. Each unit consists of three cars of which one is powered. Modern features for the seventies were air suspension and disk brakes. Most were used around large cities, but some were also used for longer-distance services.
In 1991, some units lost their middle trailer, increasing the acceleration. In the nineties, they were modernized and renamed to series 470. In Spain, their withdrawals came between 2008 and 2011. After that, 68 units were exported to Chile and Brazil, where they are being called UT 440 and UT 470.