SHANGHAI -- China will require nonbank payment apps such as Ant Group's Alipay to report new products and stock market listings to authorities, seeking to regulate a fast-expanding financial technology sector that has become a vital part of the way Chinese pay for transactions. The People's Bank of China, the central bank, will implement the new disclosure measures on Wednesday. The directives require operators to report about significant business matters before and after the fact. Initial public offerings and capital increases have been categorized as significant matters, along with rollouts of new products and services. Partnerships with a non-Chinese company...