By Olga Razumovskaya 
 

MOSCOW--OAO Gazprom's (GAZP.RS) chief executive said Monday his company was seeking Moscow's approval to provide Ukraine a discount on natural gas prices for three months beginning April 1.

Alexei Miller said in televised comments: "We consider the three-month period optimal. Firstly because the spring-summer season is beginning and also because of the high volatility of prices on external gas markets."

Ukraine's state-owned oil and gas company Naftogaz said earlier on Monday that it had sent a letter to Gazprom seeking a longer period. It wants to extend the discount winter package to the end of winter of next year.

On March 20, Russia and Ukraine restarted talks over gas supplies as the temporary deal that gave Ukraine a discount runs out at the end of March. The talks are being mediated by the European Union, which receives around a quarter of its gas imports from Russia, around half of which come via Ukraine. Ukraine has said that Russia's gas price is too high.

Ukrainian Energy Minister Volodymyr Demchyshyn said that Ukraine will stop buying gas from Russia from April 1 and will instead buy gas from Europe. The gas price is expected to fall in the third quarter as it is linked to the oil price with a time lag of several months.

The temporary deal was struck back in October between Russia and Ukraine and ensured Russian gas was being transited to the EU without interruptions and to last Ukraine through a heating season.

At the European Commission-mediated talks on March 20 the sides discussed the possibility of extending the discount deal between Russia and Ukraine. No documents were signed during those talks but Russia said it would consider granting Ukraine a discount. Ukraine said it would buy large quantities of gas to fill up its storage facilities and to ensure uninterrupted transit to the EU during the next heating season.

The European Commission spokesperson said that new tri-lateral talks will be held in April.

Nick Shchetko in Kiev contributed to this article.

Write to Olga Razumovskaya at Olga.Razumovskaya@wsj.com