A UN-backed court for Lebanon will sentence two Hezbollah members in their absence Thursday for the 2005 assassination of former premier Rafic Hariri in what could be the cash-strapped tribunal's final act.

The Special Tribunal for Lebanon (STL), which is based in the Netherlands, found Habib Merhi and Hussein Oneissi guilty on appeal in March over a huge bombing which killed Hariri and 21 others and injured 226.

But they are unlikely to ever spend time behind bars as the Lebanese Shiite Muslim movement Hezbollah has refused to hand over the pair or a third man, Salim Ayyash, who was sentenced to life imprisonment in 2020.

Meanwhile the STL, which is estimated to have cost between $600 million and $1 billion since it opened in 2009, has warned it will close imminently due to a shortage of funds.

The court said in a statement that it will announce the sentences for Merhi and Oneissi at 2:00 pm (1200 GMT) on Thursday.

Sunni billionaire Hariri, who had stepped down as Lebanon's prime minister in October 2004, was killed in a February 14 2005 suicide blast targeting his armoured convoy on the Beirut seafront.

The attack triggered protests that drove Syria out of Lebanon after a 29-year military deployment.

The court was born out of a United Nations Security Council resolution and eventually tried four suspects in absentia: Ayyash, Merhi, Oneissi and Assad Sabra.

Lack of funds

The case relied almost exclusively on circumstantial evidence in the form of mobile phone records that prosecutors said showed a Hezbollah cell plotting the attack.

The STL originally convicted Ayyash and cleared the other three men.

It said there was no direct evidence of Damascus or its ally Hezbollah's involvement, but that the attack probably involved state actors and that the state with most to gain was Syria.

But in March it found Merhi and Oneissi guilty after an appeal by prosecutors, saying the original trial judges had "erred" by saying there was a lack of evidence. They upheld the acquittal of Sabra.

All three convicted men remain at large as Hezbollah leader Hassan Nasrallah has refused to hand over any of the suspects or to recognise the court.

Dogged by political issues in Lebanon and controversy over its huge cost and slowness, the court said last July that it would have to close after dealing with all outstanding appeals as it was running out of money.

The closure means a further trial against Ayyash in a separate case involving three attacks targeting Lebanese politicians in 2004 and 2005 is now unlikely to ever take place.

The STL draws 51 percent of its budget from donor countries and the rest from Lebanon, which is grappling with its deepest economic crisis since the 1975-1990 civil war.