If the two countries fail to settle on three names, including that of the chairman, by tomorrow, the matter will be decided by a 'draw of lots'.

The treaty states that once the process of arbitration is initiated by any of the two countries, the umpires and the chairman have to be appointed within 60 days.

The draw of lots will involve the UN, the World Bank and some institutions of international repute as per the provisions of the 1960 Indus Waters Treaty.

The names were exchanged during a meeting between representatives of both sides in Islamabad on Tuesday, sources in the Government said.

Both sides suggested two names each for the post of chairman and two names each for the other umpires.

Among the two names, India is learnt to have proposed the name of former Justice of Australian High Court Michael Kirby for the post of chairman.

It also proposed UK-based Prof Asit K Biswas as the technical expert. Biswas is an expert on issues related to global water management.

The Indian side led by Chairman, Central Water Commission A K Bajaj also recommended Prof Laurence Boisson de Chazournes of the Netherlands as the legal expert. De Chazournes is on the Board of Directors of an organisation, International Dispute Settlement.

Pakistan, on its part, is learnt to have suggested names of Jordanian national Awn Shawkat Al-Khasawneh of the International Court of Justice and Edith Weiss Brown, a scholar on water management for the post of chairman.

Pakistan has recommended names of one Dutch professor for technical expert and a UK national for the legal expert.

The two countries, which have agreed on international arbitration, had been having a dispute over how to finalise the three neutral umpires who will supervise the legal battle between the two sides in a court of arbitration.

The two countries have already nominated two legal experts (arbitrators) each to contest their case over the power project being built in Jammu and Kashmir.

Accusing India of breaching the provisions of the 1960 Indus Water Treaty by diverting the water of the Jhelum tributary for its Kishenganga hydel power project, Pakistan sought international arbitration in May this year after the two countries failed to resolve the issue bilaterally for over two decades.