A confidential document seen by the Financial Times and Italian newspaper Il Riformista lists 34 Iranian entities and 10 individuals believed to be linked to covert nuclear or biological weapons programmes, the report added.
European diplomats gave differing interpretations of the reasons behind the list, the FT said.
Some said it was intended to provide U.S. President Barack Obama's administration with a "bigger stick" option in continuation of the existing carrot-and-stick approach towards Iran.
Others said the three European Union nations wanted to influence a more hardline outcome of Washington's review of its Iran policy expected to be completed next month.
Obama has said the United States is prepared to talk to Tehran, in a break from his predecessor's approach, but his administration has also warned of tougher sanctions if Iran refuses to halt its nuclear work.
The EU trio together with the United States, China and Russia comprise a group of world powers trying to resolve a stand-off with Iran over its nuclear programme.
Western powers suspect Iran's nuclear programme is aimed at building an atomic bomb. Tehran says it is purely for peaceful power generation.
The United Nations Security Council has imposed three rounds of sanctions on Iran for refusing to suspend uranium enrichment.
All the individuals on the new EU-wide sanctions proposal face penalties for the first time, the report said. They include the commander and deputy head of the paramilitary Basij force, it added.
State-run organisations named for the first time include Sharif University of Technology, Iran Insurance Company, Iran Air Cargo, Iran Space Agency and Razi Institute for Serum and Vaccine Production.
Six banks and their Tehran headquarters are named, including Bank Tejarat, one of Iran's largest commercial banks, for the first time.
(Editing by Dominic Evans)
