Mr Xi, 53, will replace Han Zheng , the city's mayor, who has been Shanghai's acting party secretary since September when Chen Liangyu , the former party boss and a member of the Communist Party's powerful Politburo, was sacked and arrested for corruption.

Zhang Gaoli , the party secretary of Shandong and also a rising star, will replace Zhang Lichang as the party secretary of Tianjin, while Li Jianguo , the party secretary of Shaanxi, will succeed Zhang Gaoli as Shandong's party boss.

Zhao Leji , the party secretary of Qinghai, will become the party secretary of Shaanxi, while Qiang Wei , a deputy party secretary of Beijing, will become Qinghai's party chief.

The latest reshuffle is expected to fuel already intense speculation that more leadership changes are pending in several other key provinces and municipalities, including Beijing, Guangdong and Jiangsu .

That would pave the way for sweeping reshuffles of the party's Politburo and its Standing Committee, the country's highest governing body, at the party's 17th congress, scheduled for autumn.

Mr Xi's appointment is also likely to signal that the central government will soon wrap up its anti-graft investigation in Shanghai, where a dozen senior municipal government officials and prominent businessmen have been arrested for their alleged involvement in a 3 billion yuan scandal over the city's pension fund which culminated in Mr Chen's sacking.

Until recently, some overseas media had speculated that Liu Yandong , the minister of the United Front Work Department, was a frontrunner for the top party post in Shanghai.

However, analysts said the promotion of Mr Xi, known for his open and pro-business outlook, should not be a big surprise because he was one of the most prominent princelings - children of former top government officials and party elders. His father is the late Xi Zhongxun , a former top party official.

The announcement of the appointments of Mr Xi and the other officials could come as early as today, sources said.

It remains unclear whether Mr Han will continue as Shanghai's mayor or, as widely rumoured, become a governor or party secretary of an industrial province.

The promotion of Zhang Gaoli, Shenzhen's party secretary in the late 1990s, is also not unexpected. As Tianjin party secretary, he is expected to become a Politburo member. Zhang Lichang, whom he replaces, has reached retirement age.

Mr Qiang, the top Beijing official in charge of law and order, made his way up from the Communist Youth League, the power base of President Hu Jintao .

It remains unclear who will take over as Zhejiang party boss but sources said Zhao Hongzhu, a deputy minister of the party's Organisation Department in charge of personnel reshuffles, was a strong candidate.

Mr Xi had been widely tipped to play an important role in the new leadership lineup following the 17th party congress, at which Mr Hu is expected to consolidate his power by removing the remaining influence of his predecessor Jiang Zemin and promoting his supporters to the top echelons of power.