Jason Blick, head of Berrymans Lace Mawer's Dubai office, says: "I have high expectations of the Iranian market.
"We are looking for an association with a firm in Tehran and have approached three firms."
Berrymans is in talks with Tehran-based law firms Dr Behrooz Akhlaghi & Associates, Torossian Avanessian & Associates and Dr Dashtara & Associates.
Blick says a link-up would win the firms work on large infrastructure projects and his firm is currently tendering for a number of such projects in Tehran with its existing construction clients.
"It is very appealing for pro-active law firms if they are prepared to broaden their remit into professional services," he says.
Berrymans formed a consortium with Deloitte & Touche for World Bank work and is also working with another big five accountancy firm, which Blick was unable to name.
Although he does not rule out a merger, he says: "Joint ventures are ideal."
Martin Amison, head of Trowers & Hamlins' international department, says: "We have been dipping our toes in Iranian waters.
"For the time being we would not have an on-the-ground presence. We would form an association with at least one local firm."
Amison has his eye on larger-scale oil and gas and major infrastructure projects work.
He says multinational companies are now showing an interest in the country.
A source close to the market at Clyde & Co, which works closely with Iranian firm Pars Associates, says: "We went through the excitement years ago but came to the conclusion that setting up an office did not make sense."
Iran is rich in natural resources including oil and gas, but needs foreign investment and is pushing to market itself to European investors.