Alibaba (BABA) - Get Report founder and executive chairman Jack Ma cancelled a speaking appearance at a U.S.-based anti-counterfeiting conference this week in the latest sign of tension between the Chinese e-commerce giant and prominent brands that say Alibaba doesn't do enough to prevent the sale of counterfeit goods on its sites.

In April, the International Anti-Counterfeiting Coalition, which has more than 250 members in over 40 countries, had granted approval to Alibaba to join the IACC as part of a new membership category comprising intermediary sellers. But many IACC members, including Michael Kors (KORS) and Tiffany (TIF) - Get Report, objected to Alibaba's admission, and the IACC said on May 13 that it was reconsidering Alibaba's membership.

In response, Alibaba issued a statement on Tuesday from Jennifer Kuperman, its head of international corporate communications, saying that Jack Ma would be withdrawing as the scheduled keynote speaker at the IACC's spring conference in Orlando, Fla., on May 19, and that Michael Evans, the president of Alibaba Group, would speak instead.

"Alibaba remains firmly committed to the protection of intellectual property rights and combating counterfeits," wrote Kuperman. "We believe the most effective way to solve the counterfeiting problem is through strong industry collaboration. ... We believe the IACC's suspension of the general membership category is a step in the wrong direction and regrettable. It highlights a fundamental difference in how we want to solve this problem."

Alibaba declined to comment any further beyond the company's written statement.

Alibaba has been dogged for years by complaints about counterfeit goods for sale on its main commerce platforms, Taobao and Tmall. It recently embarked on a campaign to crack down on counterfeit goods by requiring sellers to show proof of authenticity and punish noncompliant merchants.

Henry Guo, an analyst at ITG, said that Alibaba's reputation could take a small hit from the current tensions with the IACC but that the conflict likely wouldn't affect the company much in the long term.

"I don't see any impact on the core business of the company," said Guo.

Shares of Alibaba were trading essentially flat at $79.31 early Wednesday afternoon.

Guo added that he feels Alibaba has been working diligently to reduce the amount of counterfeit goods on its sites, expending significant resources in doing so, but that the problem will take several years to solve completely.

"Alibaba has so many millions of sellers on it, so [counterfeiting is] not that easy for them to solve," said Guo. "They also need to educate sellers because in China, most people don't have this kind of idea that selling fake goods is really that illegal -- it's a very different concept in China."