Lawmakers on Monday urged the government to rethink how it holds power companies to account after a power outage last month provided Hong Kong Electric with an opportunity to increase its profits.

The outage affected more than 40,000 customers, but because it was fixed within 65 minutes, the company will be able to slightly increase the return it is allowed under its operating agreement with the administration.

During a Legislative Council meeting, Roundtable lawmaker Michael Tien said the city's two power companies should face penalties for disruption, similar to those handed to the MTR Corporation for train service glitches.

"If there is nothing wrong, they will not be penalised. Otherwise, they should be penalised according to the severity of the incident," Tien said.

"Depending on the duration of suspension, the MTR receives a penalty. Why can't [the government] develop a similar mechanism for the power companies?" Tien asked.

The lawmaker also urged the government to lower the companies' permitted returns, to bring down electricity prices.

Secretary for Environment and Ecology Tse Chin-wan said the government will consider the suggestions in its upcoming interim review of the Scheme of Control Agreements with the power firms.