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

Canada, Ukraine and other nations who 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.

Tehran 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. Tehran already faces demands for compensation and a full investigation into the shooting down.

Iran's Civil Aviation Organization 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 U.S.-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 U.S. National Transportation Safety Board and France's accident agency BEA but said Tehran had not received a positive response.

(Reporting by Babak Dehghanpisheh; Writing by Alexander Cornwell; Editing by Edmund Blair and Michael Perry) ((; Reuters Messaging: