HONG KONG — One of Hong Kong’s largest developers announced Wednesday that it had sold an apartment for 439 million Hong Kong dollars, setting a record, just hours after the city’s chief executive warned that the city might be facing a real estate bubble.

The deal, valued at the equivalent of $56.6 million, set a record price per square foot for Hong Kong, and the developer, Henderson Land, said it was not aware of a higher figure’s having been paid anywhere else.

Henderson Land declined to disclose the buyer’s name but said it was a company registered in Hong Kong. The buyer’s representative spoke the local dialect with a strong mainland Chinese accent and appeared to be spending money earned on the mainland, a Henderson representative said.

As China’s economic recovery has gathered force this autumn, wealthy Chinese are pouring fortunes into Hong Kong real estate, producing a powerful surge in prices for luxury real estate. Hong Kong pegs its currency to the U.S. dollar and links its interest rates to American rates; with a flood of money pouring into local banks, adjustable-rate mortgages are available in Hong Kong for an initial rate as low as 2.05 percent, fueling real estate speculation.