Chinese regulators are considering a ban on short-term US dollar bond sales in Hong Kong that are an important borrowing tool for property developers and local governments, raising the prospect of funding difficulties for companies that are already highly indebted.

Since 2015, the National Development and Reform Commission, the state planning agency, has required Chinese companies to register with the agency before issuing foreign-currency debt in Hong Kong and other offshore markets.

The so-called “registration” process has effectively served as an approval requirement, but it does not apply to notes with a maturity of less than one year — a loophole that property developers and other companies have heavily exploited since last year, as China’s crackdown on debt choked off onshore financing for many borrowers.