DAMASCUS (AFP) - Syrian President Bashar al-Assad and King Abdullah of Saudi Arabia on Thursday buried the hatchet over Lebanon and urged the formation of a national unity government. Assad and Abdullah, speaking at the end of a landmark two-day visit to Syria by the Saudi monarch, underlined the importance of the agreement amongst the Lebanese, who (are likely to) find common ground to form a government of national unity, state news agency SANA reported. Lebanon has been without a government since a general election in June, because Riyadh-backed prime minister-designate Saad Hariri has failed to reach agreement with the Hezbollah-led bloc supported by Syria. A national unity government is the basis for stability, unity and strength in Lebanon, SANA cited the Syrian and Saudi leaders as saying as Abdullah rounded off his first visit to Damascus since taking the throne in 2005. In another sign of improving ties, the two regional powerhouses agreed to promote bilateral trade and investment, the news agency said. Syrian FM Mohammed al-Hussein and his Saudi counterpart, Ibrahim Assaf, said the volume of trade, currently only two billion dollars a year, will begin growing in the coming days, SANA said. We have decided to remove the difficulties hindering commercial exchanges, notably the taxes recently imposed by Syria on products exported to Saudi Arabia, such as olive oil and ceramics, Hussein was quoted as saying. Syria was the main powerbroker in Lebanon for nearly 30 years until the 2005 murder of Hariris father Rafiq, a five-time prime minister who was close to the Saudi monarchy and also a Saudi national. There were widespread suspicions that Syria was behind the killing, something Damascus has consistently denied. The assassination further soured relations between Syria and Saudi Arabia, which had already been damaged by the US-led invasion of Iraq in 2003. Riyadh has also been at odds with Damascus over its warm relations with Saudi Arabias rival Iran and its support for Hezbollah. In early July, Riyadh named a new ambassador to Syria after leaving the post vacant for a year, and a visit by Abdullah has been in the works since that time, Saudi officials say. The summit between Assad and King Abdullah acknowledges the mutual interests both countries have in Lebanon and that neither can alone have the upper hand, said Nicolas Nassif, a columnist for Lebanons Al-Akhbar newspaper which is close to the Syrian-backed minority bloc in parliament. Saudi Arabia wants Saad Hariri to succeed in his bid to form a government, he told AFP. And Syria considers that the oppositions participation in the new government will outweigh their loss in the election. The only central dispute between Syria and Saudi Arabia was and remains Lebanon, wrote columnist Sateh Nureddine in As-Safir, another pro-opposition Lebanese newspaper. Ali Hamadeh, a columnist with the pro-Hariri daily An-Nahar, warned that it was still too soon to know what impact the summit would have for the role of Iran, which has been Syrias main regional ally for some three decades and is also a leading backer of its co-religionists in Hezbollah. The question is: What is the Iranian stance towards Syrian-Saudi rapprochement? And will they release their hold over the Lebanese government? he said.