BAGHDAD, Iraq - A suicide bomber walked into a Shiite mosque in the northern city of Mosul on Thursday and detonated explosives strapped to his body, killing 47. The attack occurred as senior Shiite and Kurdish officials said that they had reached an agreement in principle on forming a coalition government, but were still negotiating some sticking points. They have agreed that a transitional basic law approved last spring will be the basis for a new government, and that Sunni Arabs should be given prominent government posts. The transitional law says, among other things, that Islam should be one of the sources of legislation rather than the sole source.

If the main Shiite umbrella group and the Kurdish alliance do hammer out a final agreement, then they will have enough seats for the two-thirds vote in the constitutional assembly that is required to form a new government.

The suicide bombing took place in midafternoon as mourners packed into the Sadaan mosque in eastern Mosul's al Tamin neighborhood for the funeral of a man who had died two days earlier, said Sadi Ahmed Pire, the head of the Mosul office of the Patriotic Union of Kurdistan, one of the two main Kurdish political parties.

The bombing was the latest in a bloody insurgent campaign to sow civil conflict here by striking at Shiites and Kurds. Last month, about 70 people were killed in a series of suicide bombing attacks on worshippers celebrating the Shiite holiday of Ashura.

Most of those killed in the bombing on Thursday were Shiite, Kurds and Turkmen, Pire said. Mosul, a city of 2 million, is a caldron of ethnic groups, with the eastern part of the city mainly controlled by Kurds. The insurgency in Mosul is believed to be led by Sunni Arabs, who live mostly in the city's western quarters.

The bombing in Mosul followed intense negotiations between Shiite and Kurdish leaders. The winners of the Jan. 30 elections, particularly the Shiites, have come under intense criticism recently for allowing negotiations over a new government to drag on.

Adnan Ali, a deputy of the Dawa Islamic Party, whose leader is the Shiite nominee for prime minister, said the Shiites and Kurds drafted a document Wednesday that lays out the guiding principles under which they will form a coalition. The two sides have agreed that the transitional law approved last spring will be the underlying foundation of the government, Ali said. Although some religious Shiites have been pressing to make Islam the foundation of all Iraqi law, the transitional law does not make Islam the sole source of legislation.

The Shiites and Kurds are also trying to bring Sunni Arab leaders, many of whom boycotted the elections, into the political process to dampen the insurgency and isolate those who carry out attacks such as the one in Mosul. If the former governing Sunnis continue to feel disenfranchised, many Iraqi leaders say, the chances of a full-scale civil war will grow.