Deputy Foreign Minister Abbas Araghchi said the plan's formal name was An End to the Unnecessary Crisis and a Beginning for Fresh Horizons.
He described the plan, which was delivered to the west in a PowerPoint presentation, as having many new ideas but said negotiators had agreed to keep the details confidential, adding: "We think the proposal we have made has the capacity to make a breakthrough."
Tehran is under international sanctions that are biting deeply into its troubled economy but since the election of reformist Iranian president Hassan Rouhani in June, Iranian officials have said they are ready to compromise with the West.
Britain, the US, Russia, China, France and Germany are eager to test whether those words will translate into real progress such as increased international monitoring and scaling back on Tehran's uranium enrichment.
The first session of the two-day talks in Switzerland - the first since Mr Rouhani's election - lasted more than two hours.
Iran's state TV, which closely reflects government views, said Tehran offered to discuss uranium enrichment levels. No deal is expected in this round of talks.