Japan will begin negotiations with Iran on a bilateral investment pact next week, Japan said, and aims for agreement as soon as possible to allow Japanese companies to rebuild a presence in the oil-rich country.Iran reached a landmark pact in July with the United States, Germany, France, Russia, China and Britain on limiting it nuclear programme to ensure it is not put to making bombs in exchange for the lifting of economic sanctions. Since then, international delegations have been flocking to Teheran seeking business in the biggest economy to rejoin the global trading and financial system since the break-up of the Soviet Union in 1991.Japan will decide on its sanctions, which include a ban on new investment in Iranian oil and gas projects, while watching other countries' moves, a Japanese foreign ministry official said.Japan's delegation at three days of talks in Teheran beginning on Monday will be led by Masaaki Kanai, head of the Foreign Ministry's second Middle East division, the ministry said in news release.