LUANDA (Reuters) - President Jose Eduardo dos Santos was re-elected head of Angola's ruling MPLA party on Wednesday, a move that signals the 67-year old leader plans to extend his three-decade long rule of one of Africa's top oil producers.

Dos Santos was the only party member running for the top post at a party congress in Luanda. The MPLA also elected new members to its Central Committee, the party's top-decision making body.

The four-day MPLA congress, which ends on Thursday, has been marked by calls from dos Santos for his party to do more to fight graft and poverty in a country where an estimated 60 percent of the 16.5 million-strong population live in desperate conditions, according to dos Santos.

Angola's opposition parties and rights groups have accused dos Santos of clinging on to power after repeatedly delaying presidential elections since the end of Angola's 27-year civil war in 2002.

Dos Santos recently said presidential elections would take place after a new constitution, expected to be ready in the first quarter of 2010, is approved by parliament. His party plans to change the constitution for the president and parliament to be elected through a single poll instead of two -- as is currently the case.