china s shanda buys stake in sina chinese online game operator shanda interactive entertainment has bought a 20% stake in sina  the country s biggest internet portal firm.  the move may be a precursor to a full takeover  with analysts saying that a better-known international firm may also now show an interest in sina. shanda said that it may boost its stake in sina  even buying it outright. a merger would create a firm that offers online role-playing games  news  entertainment and wireless messaging.  sina said that the purchase of a stake by shanda would have no impact on its business.  the board of directors said in a statement that it would  continue to act in the best interests of all the company stakeholders  including shareholders  employees and customers . both companies are listed on the new york stock exchange s (nyse) technology-dominated nasdaq index. in a filing with the us securities and exchange commission  sina said its shares were purchased between 12 january and 10 february for about $230m. rumours about a possible takeover boosted sina s shares by more than 10% on friday. they added an extra 6.4% to $27.24 in electronic trading after the trading session had finished. and there may be more gains amid bid speculation when trading resumes in new york on tuesday after monday s public holiday  analysts forecast.  there could still be some potential parties that could still counter bid   said wallace cheung  an analyst at dbs vickers.  even though shanda has 20% of sina  they still have quite a long way to take full control.  however  mr cheung noted that a foreign company trying to take control of a chinese internet portal firm  with its ability to filter and pass on news  may not be viewed very favourably by beijing.