China's market regulator released new anti-monopoly guidelines on Sunday that target internet platforms, tightening existing restrictions faced by the country's tech giants. The new rules formalise an earlier anti-monopoly draft law released in November, and clarify a series of monopolistic practices that regulators plan to crack down on. The guidelines are expected to put new pressure on the country's leading internet services, including e-commerce sites such as Alibaba Group's Taobao and Tmall marketplaces or JD.com. They will also cover payment services like Ant Group's Alipay or Tencent Holding's WeChat Pay. The rules, issued by the State Administration for Market Regulation (SAMR) on its website, bar companies from a range of behaviour, including forcing merchants to choose between the country's top internet players, a long-time practice in the market.