Karachi: Pakistan's commercial capital Karachi, a city of more than 13 million, suffered a major power outage yesterday when the country's main power utility cut the supply because the city's power company had not paid its bills.

The Water and Power Development Authority (Wapda), Pakistan's main state power utility, cut its 300 MW supplies at around 8am local time. "As a result the entire system tripped," said Syed Sultan Hasan, spokesman for the Karachi Electric Supply Co (Kesc), which supplies power to Karachi.

Tahir Basharat Cheema, spokesman of Wapda, said supplies were cut because dues had not been paid.

"Kesc owes 34.80 billion rupees ($554 million) to us and we have been writing to them every week to make at least some payments," said Cheema.

"But let alone making payments, they're not even replying to our letters."

Kesc's Hasan said the company was in contact with Wapda to ensure restoration of supplies.

"They have restored partial supplies, and after that we have also started restoring electricity," he said.

"But it will take time before the complete system is back on track."

Officials said while port and industrial operations were normal, a prolonged breakdown could cause major disruptions. Many factories and offices rely on own generators.

Pakistan has been suffering acute power shortages because of inadequate generating capacity, hefty losses and theft of electricity from power lines.

Many people cited power cuts, along with rising prices and food shortages, when complaining about the government in the run-up to elections last month. Opposition parties won the most seats in the vote while the former ruling party lost badly.

But Karachi has been worst hit because of chronic infrastructure and management problems. Power theft in the city takes place through illegal connections, and meters made to go slowly, often arranged through bribes.

Frequent and prolonged power cuts often lead to protests, with people burning tyres and blocking roads, and at times clashing with police.

Ongoing problems

The Kesc was privatised in 2005, and a consortium led by Saudi Arabia's al-Jomaih group and Kuwait's National Industries Holding are the majority stakeholders.

But that has not solved the problems. Kesc officials complain about factories as well as government offices not paying their bills.

They say it would take up to five years to overhaul the grid and meet the city's growing power demands.

Karachi is Pakistan's biggest city and home to many industries, the country's two main ports and its main stock market.