HARIPUR, Nov 2: Work on preparing design of much-awaited fourth extension project of Tarbela Dam is expected to complete by Sept 2011, facilitating launch of construction work on a power house.

Sources told Dawn on Tuesday that the World Bank had disbursed $6 million for preparing design and tender documents of the fourth extension project some four months back. The project would be executed by two UK and France-based companies.

Under an agreement designing and tenders of the project would be completed by Sept 2011 after which work on construction of power house and other related infrastructure and installation of machinery would begin.

The World Bank, according to official sources, had already pledged $800 million for the completion of Tarbela Dam's fourth extension project which was approved way back in mid nineties but delayed for unknown reasons.

Sources said under the project a power house would be constructed on the fourth tunnel of the Tarbela Dam with two new power generators of 480 megawatts each. Presently Tarbela Dam has 14 power units with installed capacity of 3,478 megawatts.