By Yi Wei Wong

Hong Kong-listed casino companies with operations in Macau plunged in Wednesday morning trade, weighed by fears of stricter regulations in the Asian gaming hub.

Shares of six casino companies, including Sands China Ltd., Wynn Macau Ltd. and MGM China Holdings Ltd. were down between 17% to 26% after Macau hinted at tighter supervision and regulations for gaming licenses, which analysts said could cause uncertainty for casinos regarding capital management and day-to-day operations.

The Macau government released a document Tuesday that included recommendations such as only allowing gaming-license holders to distribute profit to shareholders after gaining government approval, and for government representatives to directly supervise gaming companies, among other measures. The release comes as officials are embarking on a 45-day public consultation process to revise the city's gaming regulations.

Macau Secretary of Economy and Finance Lei Wai Nong told a press conference that Macau is working toward the "healthy and sustainable development" of the casino industry, focusing on improvements to casino regulatory systems, according to analyst reports.

Industry analysts expect regulatory changes to also impact licensing, which could affect the six casino companies, all of whom have licenses that are set to expire in June 2022.

Investment bank JPMorgan downgraded Macau casino stocks under its coverage to underweight or neutral from an overweight rating, citing a lack of clarity on how stricter regulations might affect casinos.

"We admit it's only a 'directional' signal, while the level of actual regulation or execution still remains a moot point," JPMorgan said in a note on Wednesday.

"That said, we think this announcement would have already planted a seed of doubt in investors' minds, which is probably enough to de-rate these names until clarity emerges on key points, an event that's unlikely to happen this year, in our view," JPMorgan said.

Sands China shares last slumped 27%, MGM China slid 17% and SJM Holdings Ltd. declined 16%. Melco International Development Ltd. was down 15%, Galaxy Entertainment Group Ltd. dropped 17% and Wynn Macau lost 24%.

Write to Yi Wei Wong at yiwei.wong@wsj.com

(END) Dow Jones Newswires

09-14-21 2345ET