Sales growth at Cettire has slowed, with the online luxury retailer on track to record just half the earnings investors expected for the six months to the end of December, a disclosure that sent shares plunging.

The company told shareholders that revenues had jumped to $155 million in the three months to September 30, a 22 per cent rise on the same period last year. Sales grew 5 per cent at the start of this quarter, Cettire said.