President Omar Hassan al-Bashir appointed al-Haj Adam Youssef as vice president, state news agency SUNA reported late on Tuesday, without giving further details.
Mostly non-Arab rebels launched a rebellion in Darfur almost ten years ago, accusing the Khartoum government of neglecting the development of the region.
Bashir mobilised troops and mostly Arab militias to crush the uprising, unleashing a wave of violence that Washington and some activists called genocide.
Youssef, a member of one of Darfur’s Arab tribes, was previously a member of the opposition Islamist Popular Congress Party that, some analysts say, had links with Darfur rebel groups.
But he later switched sides and rose to a senior position in Bashir’s ruling National Congress Party (NCP).
Will his new appointment, Youssef will be the third most senior member of government after Bashir and First Vice President Ali Osman Taha.
Two leading rebels groups rejected the appointment, telling Reuters Youssef was an Islamist from an Arab tribe who would not end the marginalisation of non-Arabs in Darfur.
“He is part of the Arabisation of Darfur. He won’t make a difference,” said el-Tahir el-Faki, a senior official at the Justice and Equality Movement (JEM), one of the most powerful rebel groups.
Ibrahim el-Hilu, a spokesman for a faction of the rebel Sudan Liberation Army, said: “We are against Youssef. He is like Bashir.”
JEM and other rebel groups have refused to sign a Qatar-brokered peace agreement which Sudan signed in July with the Liberation and Justice Movement (LJR), an umbrella groups of small rebel factions. Reuters