The International Court of Justice had exonerated Serbia of direct responsibility for killings, rapes and "ethnic cleansing" in Bosnia.
Bosnia will appeal a UN court ruling that cleared Serbia of blame for genocide, the Muslim Bosniak member of the country's presidency said on Friday.
The 2007 judgement by the International Court of Justice exonerated Serbia of direct responsibility for killings, rapes and "ethnic cleansing" in Bosnia during the breakup of Yugoslavia in the 1990s, though it said Serbia had failed to prevent genocide.
And while the ICJ ruling concluded that genocide had occurred at Srebrenica, where about 8,000 Muslims were slaughtered by Bosnian Serb forces, it did not say genocide had happened in other parts of Bosnia.
Bakir Izetbegovic, the Bosniak member of the three-man presidency alongside Serbian and Croatian peers, has engaged a lawyer without his colleagues' consent to prepare the lawsuit ahead of a 10-year deadline on February 26.
"The request for (revision) will be filed next week," Izetbegovic, who heads the largest Bosniak party, SDA, told a news conference after meeting lawyers and war survivors.
The goal is to prove that genocide was so widespread that it could not be limited to Srebrenica, he added.
Serb, Croat leaders oppose move
The Bosnian Serb and Croat leaders have opposed his initiative, saying it would violate the constitution and cause a political crisis in the volatile Balkan country.
Serb lawmakers in the national parliament have indicated they may boycott the legislature until the ICJ declares on the request.
Milorad Dodik, the president of Bosnia's autonomous Serb Republic, asked the Serb representatives in state institutions to dispute the appeal before the ICJ and launch criminal proceedings against Izetbegovic.
Izetbegovic said the revision of the judgement carried an "obvious risk" but he could not give up.
"To trade with human suffering and genocide for the sake of political stability would cause a disastrous damage to the dignity of the victims," he said.
"This is bad news," Aleksandar Vucic, the prime minister of Serbia, which provided financial and logistics support for Bosnian Serb troops during the war, was quoted as saying by Tanjug news agency.
Izetbegovic said among the new evidence to be submitted would be material from the trial of Ratko Mladic, the former Bosnian Serb general facing charges at the UN war crimes tribunal over his role in the Srebrenica massacre.
"All we want is justice and we have the right to it," said Kada Hotic, who lost her son, husband and two brothers in the genocide.