Colombian lawmakers have shot down a bill aimed at reducing the dominance of Mexican firm Claro in the wireless market, Bloomberg reports. The legislation looked to impose a market share cap, limiting players to controlling no more than 30% of the nation’s mobile subscriber base. If passed, the bill would have required the America Movil (AM) subsidiary to cut its portion of the segment by more than half. TeleGeography’s GlobalComms Database notes that Claro represented 63.5% of Colombia’s wireless market at end-December 2012, whilst its nearest rival, Telefonica’s local unit Movistar Colombia, took 24.5%. A senate committee voted 6-3 to drop the bill, arguing that the constitution already features ample measures to address anti-competitive behaviour. Claro’s position in the market has been likened to a de facto monopoly, and the cellco was forced to defend itself against threats that it might be denied permission to participate in the upcoming 4G auctions. In the event, Claro will be allowed to take part in the sale, although it will be limited to bidding for spectrum in the 2500MHz band, whilst rival operators Tigo and Movistar are restricted to airwaves in the 2100MHz and 1900MHz ranges.