Mobile phone operator Celtel Kenya has unveiled another tariff, of six shillings per minute on per second billing.

The company says the new tariff that begins on Monday, will cover between 11pm and 5am every day.

Celtel CEO David Murray said the Mambo 6 tariff is in response to customer requests for affordable mobile phone call costs.

Speaking in Eldoret, Murray called on communication companies to allow customers to call across all the networks at minimal costs.

He said the company is preparing to adhere to the Communications Commission of Kenya, directive that all operators reduce their charges to below 30 shillings by June this year.

Murray said the high charges are tantamount to penalizing customers when they choose to call other networks.

The company has embarked on an expansion of its network infrastructure at a cost of 10 billion shillings, in order to cover over 90 per cent of the country.

Murray said a 10 per cent market penetration would ensure an extra gross domestic product growth of 0.6 per cent.