This was reported on Monday by the official IRNA news agency.
Hassan Rouhani, who met visiting German Economy Minister Sigmar Gabriel, said he hopes Germany plays a "positive role" in improving relations between Iran and the EU, "as it played a positive role in nuclear talks."
Gabriel is heading a delegation of representatives from German companies, one of the first overt signs of a thaw following a deal with world powers over the Islamic Republic's nuclear program.
In response to Rouhani's comments, he said, "I am sure the business community of Germany and the German government will take stronger steps in the way you indicated," the report said.
An IRNA report earlier on Monday quoted Iranian Oil Minister Bijan Zanganeh as saying the conference will be held in late summer or early autumn and will be aimed at laying the groundwork for businesses in both countries to work together as sanctions are lifted. The last such event was held in 2002 before the imposition of international economic sanctions over Iran's nuclear program.
But despite the optimism, Gabriel warned that obstacles still remain that could affect the pace of German investment in Iran.
"Issues of human rights, civil rights of citizens and other individuals — and especially the security of Israel — are all of great significance for Germany," he said.
Israel remains strongly opposed to the deal and its government maintains it has not ruled out a unilateral military option against Iran's nuclear facilities.
Iran does not recognize Israel and supports anti-Israeli militant groups like the Palestinian Hamas and Lebanese Hezbollah. On Saturday, Iran's Supreme Leader Ayatollah Ali Khamenei described Israeli in a speech as a "terrorist, baby-killer government."
The German delegation is the first to visit Iran after negotiators struck the nuclear deal in Vienna last week. Germany was among the six world powers involved in the talks.
Iran and the Germany have a history of economic ties dating back to the 19th century. Germany was a major trade partner in the 1990s and more than 200,000 Iranians live there.