Two US giants have begun fighting over British design and engineering consultancy Scott Wilson as yesterday's 210p a share offer from URS was trumped this morning by CH2M Hill.The Colorado-based firm is offering 245p in cash for the company, worth about £189m, more than double Friday's closing price.URS, which launched its own £161m bid Monday morning, has until 5pm tomorrow to match its rival, according to a matching rights agreement signed with Wilson.It responded quickly today, confirming it "continues to consider its options" and is deciding whether to increase its offer to 245p or above.CH2M Hill says it has already bought 9.7m shares, or 13.1% of the business, and received irrevocable undertakings to back its bid from Artemis, with 1.8%, and Aviva Investors Global Services, which owns 3.2% of Wilson."CH2M Hill has a demonstrable track record of supporting and developing the businesses we acquire," said chairman Lee McIntire. "Our collaborative culture, global presence and range of expertise enable us to help such businesses access enhanced opportunities."