Shares in the Californian wine company, Robert Mondavi Corp., fell by almost 8% on Friday following a downgrade from investment bank, UBS Warburg. Warburg cut its rating from "neutral" to "reduce", saying the recent rise in the value of the stock was not warranted.

"With no visible evidence of improving fundamentals and Mondavi's balance sheet health (and returns on capital) estimated to deteriorate due to the consolidation of synthetic leases, we find it hard to justify the recent rally in the shares," UBS Warburg analyst, Caroline Levy, said.