I've always had my doubts about this passage in the SSCI report. The bottom line is that it's based on the testimony of Mayaki. From what I have been able to gather from other sources is this:

The Niger Minister of Mines in the year 2000, Yahaya Baaré, declared that during the transition government in 1999, a country « that was not Iraq » tried unsuccessfully to buy uranium yellowcake from Niger. Also, two Nigerien businessmen who resided abroad contacted the Ministry as intermediaries with the proposal to buy uranium for a nation that presumably had not signed all of the conventions against the proliferation of nuclear weapons. The identity of this third-party nation has not been revealed.

I do not know if this testimony syncs with Mayaki's. The timeline is the same.