Opera will file a complaint against Microsoft to Brazilian antitrust authority CADE on Tuesday, alleging the tech giant gives its Edge browser an unfair advantage over competitors. Opera claims Microsoft pre-installs Edge as the default browser across Windows devices and prevents rivals from competing on product merits. The company's general counsel Aaron McParlan said Microsoft locks browsers like Opera out of preinstallation opportunities and frustrates users' ability to download alternative browsers. Opera, which says it is Brazil's third-most popular PC browser, wants CADE to investigate Microsoft and demand concessions to ensure fair competition.Read more of this story at Slashdot.