China's precedent-breaking Xi Jinping gets set to bolster his power

* 19th Communist Party Congress starts Oct 18

* Xi allies expected to be promoted

* Expectations are that Xi will be given new titles

By Ben Blanchard and Philip Wen

BEIJING, Oct 16 (Reuters) - Chinese President Xi Jinping is set to amass even greater power at a Communist Party Congress this week, promoting close allies, having his guiding thought enshrined in the party constitution and possibly assuming a title to put him on par with Mao Zedong.

That is the view of multiple sources with ties to the Chinese leadership, including senior party officials, former officials and foreign diplomats who have talked to top officials. Much of it has also been signalled in various ways in the state media in recent months.

Xi was born into revolutionary aristocracy and came of age in the tumult of Mao's Cultural Revolution. Since taking office five years ago, he has cast aside decades of precedent, stamping his authority on the party's 89 million members and asserting China's rising might on the global stage.

Having been perceived as a colourless, unambitious "princeling" child of the elite before catapulting into the apex of power as a Standing Committee member in 2007, Xi has surprised time and again, leadership sources, diplomats and experts say. He has locked up political rivals for corruption, accumulated titles and pushed painful reforms for the military.

China's State Council, which doubles as the party's spokesman's office, did not respond to a request for comment on Xi's plans for the 19th Party Congress or on how the party evaluates his first five years in office.

At the congress, a twice-a-decade event that opens Wednesday, some of Xi's most trusted aides look set for promotion to the Standing Committee, such as Li Zhanshu, an advisor who worked as a junior official in Hebei province in the 1980s at the same time as Xi.

In another key break with tradition, Xi looks set to retain a key ally, Wang Qishan, in some capacity despite the anti-corruption tsar passing retirement age.

Xi could also end up being called party chairman, a role that would pave the way for him to stay in office past 2022 when precedent dictates he should step down, leadership sources say.

"Xi is now moving more in the direction of a king, of 'I am China' and 'I am the Communist Party'", said Steve Tsang, director of the China Institute at the School of Oriental and African Studies in London.

In another first, Xi has already overseen two large-scale military parades in his first term, including a dramatic display of China's rising power and military capability through Beijing's Tiananmen Square in 2015.