"Repsol and Shell are currently negotiating with the government a change" in their participation in the development of the project at
The two firms want to exchange their participation in bloc 13 for a role in bloc 20 or 21 due to rising development costs, she added.
But the Repsol spokeswoman said
"If this was the case we would not be in talks to exchange one Iranian bloc for another," she said.
Earlier Monday the Financial Times reported that the two firms had pulled out of the $10 billion (6.5 billion euro) project to develop bloc 13 of south Pars amid geopolitical uncertainty and rising costs.
The newspaper said the two firms could still participate in other blocs.
Blocs 20 and 21 will take at least a decade before they become operational while bloc 13 is expected to be developed much sooner, the newspaper added.