New Delhi, Nov. 28: Moscow’s shipbuilders have told Delhi that another $1.6-billion (about Rs 6,400 crore) contract for three stealth frigates is likely to slip behind schedule, days after asking India to pay up twice the contracted amount for the Admiral Gorshkov aircraft carrier.

Slippages in schedule invariably lead to whopping price hikes by the Russians, the Indian Navy has found over time.

India had contracted three additional Krivack-class stealth frigates on July 27 last year. But the Baltic Shipbuilders at Yantar in Kaliningrad has told India that it has not yet been able to tie up agreements with all suppliers, a senior defence ministry source said.

Separate companies in Russia are to supply weapon systems, radar and communications systems and also integrate other equipment, such as the Brahmos missile, that the Indian Navy wants on board the ships. The three frigates are to be delivered by 2011-2012.

Moscow has not officially told the Indian Navy that the delay is inevitable. But this is the understanding of navy and defence ministry officials, a team of whom went to Russia last fortnight.

A Russian delegation is expected in Delhi this week to discuss the pricing of the Gorshkov. It is also likely to give a status report on the work on the three frigates.

The team includes an official from Rosoboronexport, the main Russian agency through which all military contracts with India are executed.

The Baltic Shipbuilders has told Rosoboronexport that its deadlines for negotiating contracts with suppliers have not been met.

After concerns expressed by the Indian Navy, Rosoboronexport is now trying to form an inter-agency organisation to execute the contract.

The Indian Navy had procured its latest frigates — the Talwar, Trishul and the Tabar — also from Russia, the last being delivered in 2005.

The contract for those frigates — signed in November 1997 — had run into trouble as well. Shivering in the Siberian winter, an Indian Navy crew for the ships were kept waiting for nearly a year to take charge.

The stealth frigates now on order are of the same class as the first three but with modifications in weapons and tracking platforms.