HARARE (AFP) - Zimbabwe's ruling party on Saturday wrapped up a key congress once again anointing veteran President Robert Mugabe as party leader and putting his wife Grace on a path to follow him into power.

"I want to thank you profoundly for once again choosing me to lead you," Mugabe told the thousands of cheering supporters at the ZANU-PF's elective congress.

"I know where I come from... I am not greater than the people who gave birth to me," said the 90-year-old who has been in power in Zimbabwe since independence from Britain in 1980.

The congress also elected his wife 49-year-old Grace to head the party's powerful women's wing, which would put her higher among the contenders to succeed Mugabe.

She had won a surprise nomination in August to lead the women's league and has made no secret of her ambition to clinch the southern African country's top job.

For now her husband plans to hold onto that position as party delegates also chose Mugabe to stand as the ZANU-PF candidate in the next elections in 2018.

On Wednesday, the firebrand leader had slapped down speculation he would stand down as "foolish" and "idiotic".

He drew a line under years of unrest within the ruling ZANU-PF, which have seen key lieutenants jockey for position in anticipation that his days in power are coming to an end.

On Saturday when Mugabe announced his wife's new role in the party it was met with tepid applause that led party chairman Simon Khaya Moyo to exhort the crowd to cheer louder.

"We need a bigger applause," he said, and the delegates began shouting, "Amai! Amai!" (Mother! Mother!).

Grace Mugabe had waged a fierce campaign for the women's league post, which also puts her on the party's steering committee, disparaging her rivals including Vice-President Joice Mujuru whom she has accused of corruption and even plotting to assassinate her husband.

Mujuru, 59, widow of the country's first black army chief, did not attend the congress after failing to win a seat on the party's central committee.

With Mujuru apparently out of the succession race, eyes have turned back to 68-year-old Justice Minister Emmerson Mnangagwa.

He was himself the victim of a purge in 2004 when he lost a key ZANU-PF job after being charged for excessive ambition while angling for the post of vice president which Mujuru then won.

ZANU-PF has been riven by factionalism over Mugabe's succession for years, with the Zimbabwean strongman avoiding naming a successor.