(Sharecast News) - Rolls-Royce was under pressure on Monday after San Francisco-based activist investor ValueAct Capital Management cut its stake in the company.ValueAct sold off just over 1.9 billion shares in the aerospace and defence firm, reducing its holding from 10.94% to 9.48%.It remains the company's largest shareholder.At 1110 GMT, Rolls-Royce shares were down 2.6% at 880.20p, making it the biggest faller on the FTSE 100.