KHARTOUM, Dec. 13 (Xinhua) -- The Sudanese ruling National Congress Party (NCP) and the former rebel Sudan People's Liberation Movement (SPLM) agreed on a bill of referendum for southern Sudan, senior officials of the NCP and the SPLM announced on Sunday.

The bill paved the way for the referendum scheduled for January2011 to decide whether southern Sudan would break away from Sudan.

The officials said the agreement was reached during a meeting of the two parties chaired by Sudanese President and NCP Chairman Omar al-Bashir and First Vice President and SPLM Chairman Salva Kiir, following marathon consultations in the past few days.

The bill is to be handed over to the parliament for approval, the officials said at a joint news conference.

"We have reached full agreements on the southern Sudan referendum bill," said Nafie Ali Nafie, deputy NCP chairman at a joint press conference with SPLM Secretary General Pagan Amum.

Nafie said the two sides had also reached agreements on one bill of the popular consultation for Blue Nile and South Kordofan areas, and another on self-determination referendum for Abyei area.

He added that all agreements reached by the two sides would be referred to other political parties in the country to consult on, expecting that the two sides would reach final agreements on bills of security and intelligence service in few days.

For his part, Amum told the joint press conference that the NCPand SPLM had agreed to reform their existing partnership, adding that what they had agreed on would be referred to the council of ministers and the National Assembly (parliament).

He added that the two sides have also agreed to form a joint committee to discuss the issue of the general elections to ensure that they would be free and fair.

"This committee will also be entrusted with reviewing the NCP-SPLM relation on one part, and their relations with other political forces, on another part, to come to a common platform for honest competition among all Sudanese political forces", he said.

Amum also said arrangements were underway for return of the SPLM parliamentary bloc and other southern Sudanese parties to attend the parliament sessions.

The SPLM parliamentary bloc has been boycotting the session of the Sudanese parliament since mid-October in protest against non-endorsement bill on referendum on self-determination for southern Sudan and other bills of democratic transition in the country.