March 6 (Reuters) - A bill in the U.S. Senate that would

restrict business with China's BGI, WuXi Apptec and

other biotech companies on national security grounds faces its

first big test in Congress on Wednesday.

The draft legislation, which is designed to keep Americans'

personal health and genetic information from foreign

adversaries, will be discussed in a committee meeting and could

be changed and either moved forward for a vote or held back for

more discussion.

The bill has spurred deep concern among investors, driving a

sell-off in the shares of WuXi AppTec when news of its

introduction first reached Chinese markets last month.

As currently written, it would prohibit federal agencies

from contracting with China's BGI, MGI, Complete Genomics, WuXi

AppTec, their affiliates and other biotechnology companies

deemed of concern. It would also stop the government from

entering into contracts with companies that use their equipment

or services.

But when members of the Homeland Security and Governmental

Affairs Committee meet on Wednesday to markup the bill, it is

possible one or more company names could be stripped from the

text.

The companies have denied they pose any security threats.

The committee expects the bill to move forward on a

bipartisan basis, an aide for Senator Gary Peters, chair of the

Homeland Security and Governmental Affairs Committee said.

A companion bill introduced in the House in January accuses

BGI, a genomics company, of posing a threat to U.S. national

security through its collection of genetic data. It describes

MGI and Complete Genomics as subsidiaries and affiliates.

WuXi Apptec, which provides R&D and manufacturing services

to the pharmaceutical and healthcare industry, allegedly has

ties to the Chinese military, according to the House version of

the bill.

The companies have said the proposed legislation contains

false, misleading and unfounded allegations.

Rick Connell, WuXi Apptec's chief operating officer for the

U.S. and Europe, said the company was closely monitoring the

markup.

"We are confident that upon considering the facts, lawmakers

will understand that WuXi AppTec does not pose a national

security risk," Connell said, and is "a trusted partner to

customers in the U.S. and around the world."

BGI Group said it supports the bill's premise of protecting

Americans' personal data, but that it does not have access to

that data. It said the legislation will "drive BGI out of the

U.S." and limit competition.

Once it moves out of committee, the bill must pass in both

the full Senate and the House, and then needs be signed by the

president.