Russia has refused to sell S-300 anti-ballistic missiles system to Pakistan, rejecting Islamabad's request for the second time in a month.

Russian President Vladimir Putin is reported to have said no again to the sale of S-300 missiles to Pakistan at his Moscow parleys with Pakistan President Pervez Musharraf, official sources said.

Putin expressed Moscow's willingness to develop ties with Islamabad 'purely' on bilateral basis, without accepting any references to Russia's relations with other countries.

The sources said earlier last month Islamabad had mooted the idea of purchasing S-300 ABM system from Russia at a meeting of a working group on strategic stability.

At that time Moscow had indicated that it does "not have that level of trust" with Islamabad which could enable the supply of this state-of-the-art missiles system.