(Reuters) -A U.S. Senate committee said on Monday it will hold a hearing on March 6 on a bill that would prohibit federal agencies from contracting with China's BGI, WuXi AppTec and other biotechnology companies of concern. The bill would also stop the government from entering into contracts with companies that use the Chinese companies' equipment or services. News of the Senate bill, and similar legislation in the House, has sent shares of WuXi AppTec tumbling in recent weeks on fears it would hurt the company's large U.S. business.