Saudi Arabia wants Japan to increase its investment, which currently stands below expectations, Saudi Arabian Crown Prince Abdullah bin Abdulaziz Al Saud told Prime Minister Keizo Obuchi."There is room for further improvement in relations between Saudi Arabia and Japan," Crown Prince Abdullah was quoted by Foreign Ministry officials as telling Obuchi on Wednesday.Obuchi replied that bilateral consultations should be promoted to find ways to improve Saudi Arabia's investment environment, the ministry officials said. Obuchi added that Japan's private sector is promoting efforts to increase investment in Saudi Arabia and that the crown prince's visit will help increase Japanese business interest in Saudi Arabia, they said.On Thursday, the crown prince met with Jiro Nemoto, chairman of the Japan Federation of Employers' Associations (Nikkeiren), and other Japanese business leaders to promote cooperation between the two countries.Abdullah arrived in Tokyo for a three-day official visit Wednesday afternoon on his way home from visits to Britain, France and the United States. Abdullah, King Fahd's brother, is expected to succeed the ailing king sometime in the future.Obuchi expressed hope that the question of whether Japan will be able to retain its crucial oil-drilling rights off the Arab nation's Persian Gulf coast will be resolved as early as possible.Arabian Oil Co., Japan's largest oil producer and a firm with strong government backing, holds exclusive drilling rights in the Khafji oil field off the former neutral zone between Saudi Arabia and Kuwait. Riyadh has not yet pledged to renew Arabian Oil's exclusive rights to the concession, which is due to expire in spring 2000.The crown prince did not make a direct response to Obuchi's remark. Saudi Arabia is believed to be using the issue to pressure Japan to increase investment in the Arab country. Obuchi and the crown prince meanwhile signed agreements including an action program to build a partnership for the 21st century.