A free trade zone would open doors to Hong Kong professionals such as accountants and insurers. In particular, it could lift the restriction on SAR accountants who must pass an exam to qualify for work in the mainland. According to David Sun Tak-kei, chairman of assurance services at Ernst & Young, China allows only the Big Five accounting firms to set up joint ventures with domestic accounting firms to provide services for mainland companies. Mr Sun hoped authorities would allow Hong Kong accountants to operate in China without examination and joint venture restrictions. 'In addition, the free trade zone would increast business between Hong Kong and China, which would also increase business for accountants,' he said. Bernard Charnwut Chan, legislator for the insurance sector, said a proposed free trade zone would be beneficial if local insurance companies were allowed to serve their Hong Kong clients who operate in the zone. At present, many locally incorporated insurance companies are too small to apply for a licence in China.