BEIJING—Faced with increasing complaints about the sale of counterfeits on its websites, Alibaba Group Holding Ltd. is lobbying the U.S. government to keep its popular online bazaar Taobao and other trading platforms off its list of markets for pirated goods.

Alibaba has written to the U.S. Trade Representative’s office to highlight recent efforts to protect intellectual property, including a new mechanism the company introduced in April that is aimed at expediting requests from brands for fake merchandise to be taken off Alibaba’s platforms, according to letters posted this month to a U.S. government website for public viewing.

The two letters were submitted to the USTR as part of the government agency’s annual review of a list of what it calls “notorious” online and physical marketplaces that reportedly sell pirated goods. The Alibaba marketplace Taobao had previously been on the agency’s list of problematic markets for pirated goods. In 2012, the USTR removed Taobao from that list, citing Alibaba’s efforts to address complaints by brand owners.

In its letters, Alibaba said it has also implemented more stringent processes for verifying the identities of sellers on Taobao, where stolen identities have sometimes been used by sellers of counterfeit goods. Alibaba also said it has set up an English-language version of a platform where brand owners can register their intellectual-property rights and submit complaints and requests for items to be taken down. Previously, the site was in Chinese.

The e-commerce giant’s efforts to address the problem of fakes sold on its retail and wholesale online platforms have come under fresh scrutiny over the past year. A Chinese government regulator in January accused Alibaba of lax oversight that allowed the sale of counterfeit goods, accusations which Alibaba called unfair. Later, the luxury group Kering SA filed a lawsuit in New York against Alibaba, which said the complaint had no basis. Earlier this month, a U.S. apparel group urged the U.S. government to once again label Alibaba’s Taobao marketplace a “notorious” market for fake goods.