Ghana's Volta Aluminium Company (Valco) said on Thursday it was trying to overturn a government order to temporarily shut down two of the five pot lines serving its smelter.

Energy Minister Albert Kan-Dapaah told parliament earlier this week the closure order was due to power rationing needs and Valco had to comply by Wednesday midnight.

But Valco's director told Reuters the company had not shut any pot lines yet and had applied for a court order to restrain the Volta River Authority, the state-run power generator, from cutting electricity supply to Valco.

Charles Mensah also threatened lay-offs if Valco was forced to close the pot lines, although he said he was still confident that a compromise with the government could be found.

"We are hopeful and optimistic that we can talk through it," he said.

Kan-Dapaah said the order was motivated by a faulty turbine at the Akosombo dam, the main source of electricity in the West African country.

He said the closure of two of Valco's pot lines would allow the Volta River Authority to save 150 megawatts for other users.

Valco normally consumes about 60 percent of the power generated by the Akosombo dam and is currently in negotiations with the government over how much it should pay for electricity.

Mensah said the pot lines required a minimum of 30 days to shut down properly in order to prevent molten aluminium from solidifying and causing damage.

"They gave us 48 hours notice, and that's an industrial impossibility," Mensah said.

"If our power is cut, we'll certainly lay off staff. I can't say how many but it could be a substantial number," he said.

Valco employs 1,400 people. Its smelter in Tema, 18 km (11 miles) east of the capital Accra, produces 160,000 tonnes of aluminium per year and has five pot lines although only four are currently operational.

Pots are electrolytic cells arranged in lines and connected to a power source in which alumina, an intermediate raw material derived from bauxite, is reduced to aluminum metal.

Mensah said Valco had applied for a restraining order on Wednesday but the court had said the Volta River Authority and the government must be given adequate notice to prepare their case.

Valco's parent company, Houston-based Kaiser Aluminum (KLU) filed for Chapter 11 bankruptcy last week but said the filing did not include the Valco smelter.