Better than expected results from US rival Marriott and a ratings upgrade from Barclays Capital gave a boost to hotels and coffee bar group Whitbread Friday morning.BarCap has upgraded the stock from 'underweight' to 'overweight' ahead of Whitbread's interim results on October 13.'We believe that the previously set FY [full year] pre-tax profit guidance is likely to prove conservative and we expect consensus forecasts to be revised upwards again [after the results are announced],' BarCap said.