His visit comes just a day after the oil-rich kingdom said it had arrested a ring of alleged Al-Qaeda militants plotting airborne attacks on oil facilities and army bases, underscoring Japanese worries about stability in the region.

Abe, fresh from his first official visit to the United States for a summit with President George W. Bush on Friday, will hold talks with King Abdullah and Crown Prince Sultan bin Abdul Aziz, who is also defence minister.

He and a 180-strong business delegation will also meet Hashim Yamani, the minister of commerce and industry and senior business figures, according to the Arab News.

“Economic and trade issues, investment opportunities and economic cooperation in energy will be discussed (during the meeting),” the Saudi daily said.

Japan’s first leader to be born after World War II will also visit Egypt, Kuwait, Qatar and the United Arab Emirates on his five-day tour.

This is the second visit to the Middle East by a Japanese premier in less than a year. Abe’s predecessor, Junichiro Koizumi, travelled to Israel, the Palestinian territories and Jordan in July, saying Japan could be a neutral broker in the strife-torn region.

In Riyadh, Abe and the Saudi king plan to discuss energy security, business ties and regional issues, including the war in Iraq, Iran, and the Middle East peace process, a Japanese government official said, asking not to be named.

Japan and Saudi Arabia are expected to agree to begin a joint program to create new businesses in the country now heavily relying on oil-related industries, Japanese sources said.

The two countries are also expected to discuss investment rules, an aviation accord and an oil reserve plan, while Abe is expected to invite King Abdullah to Japan, they said.

Abe hopes to use the Middle East trip to forge a “multi-layered relationship” covering not only energy security but political, business and cultural dialogue between the two sides, the official said.

Japan is increasingly concerned by potential threats to its energy supply. It has virtually no oil or gas reserves of its own and relies for more than 70 percent of its oil supply on the four Gulf states which Abe is due to visit.

Japan has also faced competition in the region from China, which is also keenly seeking resources to fuel its rapidly growing economy.

In February, President Hu Jintao toured resource-rich African nations, amid criticism in the West that China is overlooking human rights and graft concerns in its quest.

In its effort, Japan has tried increasingly to show that it has interests in the Middle East beyond oil.

Japan came under heavy criticism in the West for bank-rolling the first Gulf War in 1991 to the tune of 13.5 billion dollars -- or 20 percent of the international contribution -- without committing personnel due to its pacifist constitution.

Learning from that lesson, Koizumi sent 600 troops to Iraq in 2003, marking the first time since World War II that Japan has sent soldiers to a country where a conflict was under way.

Abe plans to visit Japanese air personnel in Kuwait, who are flying in goods and personnel on behalf of the US-led coalition and United Nations despite Japan’s withdrawal of its ground troops last year.

Tokyo has also promoted its role as a broker in the Israeli-Palestinian conflict, most notably by planning a major agro-industrial complex to create jobs in the occupied West Bank.