Ambitious Communist Party chief Bo Xilai has been sacked from his post in a dramatic move exposing tensions in China's preparations for a generational transfer of power.     

The official Xinhua news agency on Thursday said Vice Premier Zhang Dejiang will replace Bo as Communist Party chief of Chongqing, a sprawling riverside municipality in southwest China that Bo had turned into a bastion for Mao Zedong-inspired policies.

Bo, a high-profile and telegenic contender for top leadership, has been the subject of intense speculation since Vice Mayor Wang Lijun, his longtime police chief, went to ground last month in the US consulate in nearby Chengdu until he was coaxed out and placed under investigation.

The incident and the rumours it fanned have blotted Bo's prospects of climbing to the party's top ruling body when a new generation of leaders is unveiled at a meeting late this year.

The 18th Party Congress will see China's biggest leadership transition in nearly a decade. Bo's abrupt removal implied that while he may be kept on in some position until the party succession later this year, his chances of promotion were finished, said Chen Ziming, an independent scholar in Beijing who follows party politics.

"Now it looks like Wen Jiabao's comments yesterday represented the leadership's collective view that Bo needed to go," said Chen. "This will affect the leadership politics for the 18th Congress, because this opens up new uncertainties about who is in contention."     

Premier Wen added to the cloud around Bo at a news conference on Wednesday by scolding the Chongqing government about the scandal, in the first public comment by a member of the Politburo.

Three sources with direct ties to Chongqing government officials said Bo's removal was announced at a meeting in the city. They all spoke on condition of anonymity to protect themselves and their sources.     

"The fact that the Xinhua announcement did not stress that Bo will be placed in another post means that he's probably going to be put under investigation, and there won't be any conclusion on his future until the end of that investigation," said one of the sources, a journalist with wide-ranging contacts among central officials. - Reuters