A MOVE by the US Securities and Exchange Commission to allow US mutual funds to invest in China B shares had little effect on the Shanghai and Shenzhen markets yesterday. In a letter dated Monday, the SEC indicated it would take no action against funds investing in B shares reserved for foreign investors, which started trading last year. Banks and some Hongkong-based securities companies have long lobbied the SEC for an exemption to the ban which was imposed under a US law dating from 1940. But despite the SEC move, the Credit Lyonnais Securities Shenzhen B Index was up only 8.28 points, or 0.72 per cent, to close at 1,159.74. The CLSA Shenzhen A Index rose 12.05 points or 0.4 per cent to end at 3,029.21. A few shares showed decent advances, with New World and Southern Glass among the biggest gainers. The CLSA Shanghai B Index fell back 5.84 points or 0.6 per cent to close at 974.89 while the CLSA Shanghai A Index gained 170.86 or 1.87 per cent to end at 9,325.08.