Iran has asked the Bank of England to set up special clearing accounts for its banks, but has so far been rebuffed in its effort to resolve an impasse that has left it excluded from banking in London more than a year after sanctions were lifted.

Tehran has been hoping for swift reintegration into global trade after its deal in 2015 aimed at curbing Tehran's nuclear program in return for the lifting of international sanctions. Its failure to persuade Western banks to accept its business has been one of the main choke points preventing its rehabilitation.

Banking sources from both Iran and the West, and Iranian political sources close to the talks, said Tehran has approached the Bank of England to seek clearing accounts directly with the UK central bank.