The deal was struck at a peace summit in Nairobi, Kenya, on Sunday and means the government and the Sudan
People's Liberation Army (SPLA) will have an equal share of the nation's oil reserves.
"The two delegations have reached an agreement on the division of the (southern) oil revenues," the Sudanese Al-Sahafa newspaper quoted al-Bashir as saying.
The negotiations had been expected to adjourn on Friday for the Christmas holiday, but continued after both parties failed to agree on outstanding issues.
"Both sides have told me they have agreed in principle on the oil sharing, but we are still a long way from a full wealth sharing agreement," the chief mediator, Kenyan retired general Lazarus Sumbeiywo, told Reuters.
He declined to say what proportion of oil revenue each side had agreed on.
The unresolved disputes include the SPLA's representation in a transitional government, National Assembly and civil service, and the administration of three disputed areas in central Sudan.
In October, US Secretary of State Colin Powell met Sudanese Vice President Ali Usman Muhammad Taha and SPLA leader John Garang in Kenya. Both sides were urged to come up with an agreement by the end of the year.
Colin Powell and Kenyan leader Mwai
Kibaki started the talks in October
Sudan began producing oil in 1999 from fields mainly located along an imaginary line that divides southern and northern Sudan and is producing about 250,000 barrels a day.
More than 80% of the operating oilfields are located in southern Sudan.
Peace talks between the government and SPLA began in early 2002. They have already agreed on splitting state and religion, forming a post-war army and letting the south hold a referendum on independence after an interim period.
Talks with the Sudan Liberation Army, which signed a truce in September, failed this week with both sides blaming
A second group in Darfur, the Justice and Equality Movement (JEM), has not signed a truce or begun talks with Khartoum.
The Sudanese civil war has killed an estimated two million people and left a further four million people homeless since violence broke out in 1983.