New Delhi, March 21 (IANS): India and Russia are close to resolving differences over the nuclear liability law that has held up agreement on construction of units 3 and 4 of the Kudankulam Nuclear Power Project (KNPP) in Tamil Nadu, and a contract could be signed by March-end, an official said.

An official of the Russian builders, state nuclear corporation Rosatom, told ITAR-TASS that current negotiations were at a final stage and the construction contract will be signed by the month-end, the Russian news agency reported Friday.

Following discussions earlier this year in Mumbai between officials of Rosatom and the operator Nuclear Power Corporation of India (NPCIL), both parties had approved the draft technical and economic agreement on construction of units 3 and 4 of KNPP, Rosatom had said.

India's Civil Liability for Nuclear Damages Act, 2010, which holds the operator wholly liable in the event of an accident, gives it a right of recourse against suppliers if the accident is caused by defective equipment.

The Russian position draws on the inter-government agreement of 2008, which makes the operator alone liable for possible damages at Kudankulam.

While the commercial operation of the first 1,000 MW unit at KNPP is expected in April, for the second 1,000 MW unit it is expected in December 2014.

In July 2013, the first unit attained criticality, which is the beginning of the fission process. It is generating 425 MW and is connected to the grid.

Minister of State in the Prime Minister's Office V. Narayanasamy told parliament last month that India and Russia are committed to setting up more units at the Kudankulam Nuclear Power Project, as well as elsewhere in the country.