BEIJING, Nov. 22 (Xinhua) -- Chinese share prices on Thursday slumped heavily as the benchmark Shanghai Composite Index, which covers both A and B shares, plunged 230 points, or 4.41 percent, to 4,984.16 points at the close. Heavy-weights such as PetroChina, China Pingan and Citic Securities led the downward trend. PetroChina, the country's largest oil producer, lost 4.64 percent to 35.11 yuan on the fourth day of its entry into the Shanghai Composite Index list. China Pingan dropped 7.78 percent to 106.89 yuan. Citic Securities slumped 6.39 percent to 87.24 yuan. Less than 100 stocks gained in the two markets which saw more than 1,200 losses. This could be a reaction to the corrections of the U.S. and Hong Kong markets, dealers said. Analysts said the market is under pressure resulting from insufficient capital, as capital chasing sales of new stocks was locked in by the subscr