  We report multifrequency radio observations of XTE J1550-564 obtained with
the Molonglo Observatory Synthesis Telescope and the Australia Telescope
Compact Array at the time of its discovery and subsequent hard and soft X-ray
outburst in 1998 September. A large radio flare was observed, peaking about 1.8
days after the X-ray flare. In addition, we present Australian Long Baseline
Array images obtained shortly after the maximum of the radio flare which show
evolving structure. The apparent separation velocity of the two outermost
components is v>2c.
