 Some participants in Mexicos financial market are under investigation on suspicion of engaging in absolute monopolistic practices in the brokerage market for Mexican government debt, the countrys antitrust watchdog said on Monday. The Federal Economic Competition Commission Cofece said in a brief statement an unspecified number of suspects had been summoned to shed light on what the watchdog described as efforts to manipulate the price of Mexican sovereign debt. Now they have the right to present their defense, Sergio Lopez, head of the investigative unit of Mexicos Federal Economic Competition Commission Cofece, told Reuters in an interview. 