DUBAI (REUTERS) - Iran has requested equipment it says it needs from US and French authorities to download information from black boxes on a downed Ukrainian passenger plane but Teheran had not yet received a positive response, the Iranian civil aviation body said.

Canada, Ukraine and other nations which had citizens on the flight, in which all 176 people aboard were killed when it was accidentally shot down on Jan 8, have asked Iran to send the flight data and voice recorders to experts abroad for analysis.

Teheran has given mixed signals about whether they would be handed over. Canada, which had 57 citizens on the flight, has said France would the best place to send the black boxes because it was one of the few nations with the ability to read them.

Iran's reluctance to hand over the black boxes may frustrate nations with citizens on the flight, many of whom were Iranians with dual nationality. Teheran already faces demands for compensation and a full investigation into the downing.

Iran's Civil Aviation Organisation said in its second report on the disaster that it did not have the equipment needed to download data from the model of recorders installed on the US-built Boeing 737.

The plane was brought down by Iranian air defences when the nation was on alert after tit-for-tat military strikes between the United States and Iran.

The aviation body said Iran had asked for equipment from the US National Transportation Safety Board and France's accident agency BEA but said Teheran had not received a positive response.