BEIJING — China moved on Friday to curb investment overseas by its companies and conglomerates, issuing its strongest signal yet that it wants to rein in runaway debt that could pose a threat to the country’s slowing economy.

Beijing has stepped up its efforts in recent months to restrict some of its most acquisitive companies from buying overseas assets, worried that a series of purchases by China’s conglomerates around the world has been driven by excessive borrowing.

In the latest move, a statement published by China’s cabinet, the State Council, said the authorities would punish companies for violating foreign investment rules, and establish a blacklist of businesses that did so. The statement was attributed to the National Development and Reform Commission, the commerce ministry, the foreign ministry and the central bank.

The statement pointed to acquisitions in sectors ranging from entertainment and sports clubs to hotels, but it was unclear whether or how the government would block deals.