A tunnel linking the posh Malabar Hill with Chowpatty in south Mumbai is being proposed instead of a sea-link to preserve the visual beauty of the Queen's Necklace in Marine Drive, this city's well-known sea-front.

"We have asked the Indian Institute of Technology to study whether the tunnel is feasible," Maharashtra Special Projects Secretary Sanjay G Ubale told PTI.

According to the plan, the Worli-Nariman Point sea link would connect to Marine Drive, destroying the beauty for which it is known, he said. "It is in this context that the possibility of the tunnel is being explored.

"Building a bridge would mean that you cannot remove the structure for 100 years and the beauty of Marine Drive would be gone," Ubale said.

The government has planned sea-links to decongest traffic on roads and to provide alternative connections between Mumbai and its suburbs.

In the first phase, Bandra and Worli will be linked by April 2008 at an estimated cost of Rs 1,300 crore.

The second phase will see the linking of Worli and Nariman Point at a cost of Rs 4,000 crore while the Rs 6,000-crore Nhava Sheva-Sewri sea-link will be taken up in the third phase.

The government said the "concept" for the Worli-Nariman Point sea-link is ready and five consortiums have bid for the project.

But with the city's population going down marginally according to official data, the state government wants to have a re-look before proceeding with this sea-link.

The Maharashtra government is projecting the Bandra-Worli sea-link as the city's second landmark after the Gateway of India.

The sea-link will ease traffic at Mahim Causeway with its eight-lane bridge over the sea and considerably reduce the travel time from the western suburbs to central Mumbai.

About 55 per cent of the project is complete.

Work on the Worli-Nariman Point sea-link was originally scheduled to begin in December and it was expected to be completed in four years.

The first phase of the Nhava Sheva-Sewri sea-link project includes a six-lane dual road bridge. The second phase consists of a double track rail link that will run parallel to the road link.