By Foo Yun Chee BRUSSELS (Reuters) -Amazon has offered to halt online selling and marketing practices EU antitrust regulators regard as anti-competitive to try to end two investigations and avoid a possible hefty fine, ahead of EU rules that will target such methods from next year. The European Commission in 2020 charged Amazon with using its size, power and data to push its own products and gain an unfair advantage over rival merchants that also use its platform. The U.S. online retail giant has offered to refrain from using sellers’ data for its own competing retail business and its private …