LONDON - Prime Minister Gordon Brown called on the African Union and the Commonwealth on Tuesday to help reconcile political rivals in Kenya, to stop rioting which has killed 150 people.

A spokeswoman for Brown's office said he had spoken to Ghanaian President John Kufuor, who chairs the African Union, and to former Sierra Leonean President Ahmad Tejan Kabbah, head of the Commonwealth observer mission to Kenya, to urge them to step in.

"They agreed on the urgent need to establish a process of reconciliation in Kenya facilitated by the Commonwealth and the African Union," the spokeswoman said.

"As the European Union observer mission has said, the Kenyan electoral process has fallen short of international standards."

Brown, whose country was Kenya's former colonial power, spoke on Monday to Kenya's President Mwai Kibaki, whose disputed re-election in a poll on December 27 has triggered days of rioting, and to opposition leader Raila Odinga, and urged them to talk.

"What I want to see is them coming together, I want to see talks and I want to see reconciliation and unity," Brown said. "I want to see the possibility explored where they can come together in government.

"But the first priority is that the violence is brought to an end. It is unacceptable that lives are being lost," he said.