Passenger occupancy on domestic flights operated by nine Japanese airlines using Tokyo's Haneda airport fell to a record low 56.5 percent in April, apparently due to SARS and the economic slump, the Haneda airport authority said Tuesday.

The airlines, including Japan Airlines System Corp. and All Nippon Airways Co., reported the lowest occupancy rate since data was first compiled in January 1999, according to the Tokyo Airport Administrative Office.

According to the Haneda airport authority, passengers on domestic flights in April, excluding chartered flights, rose 0.4 percent from a year earlier to around 4.44 million.

However, the number of seats available on planes was up 9.8 percent to around 7.85 million, because an increase in departure and arrival slots at Haneda airport last July led to more flights.

The occupancy rate in April last year was 61.9 percent.

The March occupancy rate was little changed from last year's levels -- at 73.3 percent -- with passenger numbers totaling 5.87 million.

The figures show that people are not only refraining from taking overseas trips due to fear of the severe acute respiratory syndrome epidemic but are also cutting back on trips within Japan, airline industry officials said.

An airline official said the decline is partly due to the way the Golden Week holidays fell this year, making it difficult for people to take consecutive days off in late April.

"The prolonged economic slump also discouraged people from going on trips," the official said.