Japan Airlines' shares were up 6 percent on their IPO price in unofficial trading on Tuesday, ahead of the airline's September 19 public listing, indicating strong demand for the stock.
One trader said the Japan Airlines shares were bid at JPY¥4,010 each on the grey market, 5.8 percent above the IPO price at JPY¥3,790.
Another dealer said he had heard of a grey market price of JPY¥4,000 to JPY¥4,015.
The IPO will raise JPY¥663 billion (USD$8.47 billion), nearly double the JPY¥350 billion injected by a Japanese government-backed fund following the airline's failure in early 2010.
The fund, the Enterprise Turnaround Initiative Corporation of Japan (ETIC), is selling its 96.5 percent stake in Japan Airlines in the IPO.