Shares of United Spirits were off to a weak start on the bourses on October 18 after it fell over 1% to Rs 1,507 after Macquarie maintained its 'underperform' recommendation on the counter citing stiff competition may likely hamper growth prospects. With a price target of Rs 1,100, the international brokerage forecasts a downside potential of 28% from the last closing price of Rs 1,528.