BRUSSELS (Reuters) -Qwant has asked France's antitrust regulator to take action against Microsoft for allegedly driving down the quality of the French search engine's results via Microsoft's Bing platform, people with direct knowledge of the matter said. Qwant, which has historically relied on Microsoft's Bing platform, wants the regulator to take interim action against the U.S. tech giant while investigating its complaint, the sources said. The French regulator has sought feedback from other search engines and will likely decide by September whether to take interim action and also whether to open a formal investigation into Microsoft, one of the people said.