With intermittent renewables playing a growing role in the country's energy mix, strengthening the network has become a key step to achieve Spain's ambitious green energy targets.
However, under Spanish rules, the amount of money energy companies can pour into networks is limited to a small percentage of the country's gross domestic product, since consumers ultimately bear the cost with their bills.
For distribution networks, for example, the limit is 0.13% of GDP.
"Today the legislation provides for a limit on investment in new networks to ensure that it is sustainable from the point of view of GDP," Ribera told reporters on the sidelines of the Spanish Investors Day event in Madrid.
"We believe that this limit can probably be raised somewhat," she added.
(Reporting by Pietro Lombardi; Editing by Ros Russell)
