BEIJING — Chinese leaders announced Friday that Bo Xilai, a disgraced Communist Party aristocrat, had been expelled from the party and would be prosecuted on criminal charges. The leaders also said they had scheduled the 18th Party Congress, the climax of China’s once-a-decade leadership transition, to start Nov. 8.

The announcements ended months of uncertainty over how the party would handle Mr. Bo, the most critical player in one of the biggest political scandals in decades, and when it would be ready to install a new generation of leaders, including Xi Jinping and Li Keqiang, the men expected to become president and prime minister.

Mr. Bo is accused, among other things, of abusing his power in the case of a British businessman who the authorities say was killed by Mr. Bo’s wife, and of taking “massive bribes” directly and through his family, according to Xinhua, the state news agency. The official report’s long list of accusations against Mr. Bo, which includes adultery, seems intended to bury Mr. Bo’s political career and diminish lingering support for him within the party and among the general public.

Political insiders said the decisions over how to move ahead on Mr. Bo’s case and the timing of the party congress were linked, because the Bo issue had to be settled to a certain degree before the leadership transition could take place. But party elders, who have an important role in deciding the leadership lineup, could still be in conflict over other significant personnel issues. The Nov. 8 date, a week after the start of a party planning session and two days after the American presidential election, gives the elders time to try to conclude their negotiations.