The couple have a deemed interest of 77.41% of Koufu's shares through holding company Jun Yuan Holdings.
Pang was appointed to Koufu's board in 1996 and Ng was appointed in 2002.
The offer price represents a premium of 15.8% over the company's last closing price, and values Koufu at $425.8 million.
Koufu called for a trading halt on Dec 29 morning. Shares in Koufu closed 1 cent lower, or 1.5% down, at 66.5 cents on Dec 28.
