"We have come to an understanding on the coalition agreement. We do have an agreement," he said.
He said that further information on the deal between Mwai Kibaki, the president, and Raila Odinga, the leader of the opposition Orange Democratic Movement (ODM), would be given at 4pm (1300GMT).
Annan had suspended talks on Tuesday after negotiators for either side could not agree on a deal.
Primary in disagreements was the level of power to be assigned to the prime minister.
The crisis ignited after disputed presidential elections on December 27, which the ODM claimed was rigged.
More than 1,500 people were killed in the rioting and tribal clashes which followed.