JOHANNESBURG (Reuters) - South Africa's JD Group shares slumped over 4 percent on Friday after UBS cut its rating on the furniture retailer to "sell". "We've downgraded our twelve month rating from neutral to sell with a price target of 28 rand," a UBS trader told Reuters. JD Group's shares were trading down 4.23 percent at 29.21 rand at 1138 GMT, with the JSE Securities Exchange Mid-cap index 0.04 percent firmer at 28,443.57 points. "It's in a constant downward spiral ... The higher interest rates are hurting it," Garth Mackenzie, head of derivatives trading at BoE Private Clients said. Consumer spending in Africa's biggest economy has eased over the past year as heavily indebted South Africans responded to interest rates that have been raised by 450 basis points since June 2006. | 
