Gasoline rates in Bulgaria have climbed to a new record high, stoking fears of a new wave of price hikes of related commodities.

A liter of gasoline A-95 traded at BGN 2.53 per liter on Saturday, as diesel hit BGN 2.59 per liter, approaching a peak of BGN 2.59 per liter registered in March.

A liter of naphtha sold for BGN 2.51-2.52 per liter on Saturday, while LPG had a price tag of BGN 1.25 per liter.

The latest price spike came after Lukoil Bulgaria, owner of the sole crude oil refinery in the country, increased wholesale fuel prices on Friday.

Since the beginning of July, gasoline prices in the country have grown by around BGN 0.14, while diesel prices have added BGN 0.12.

Lukoil Bulgaria has attributed the most recent price update to the higher cost of crude oil on international markets.

If fuel prices hold at the current peak levels, this may lead to an increase in the cost of transport services, which, in its turn, will affect prices of a wide range of products.

Since the beginning of 2011, gasoline rates have gone up by 17% and diesel prices have climbed by 13%.

Diesel fuel reached a historic peak in March, settling at BGN 2.59 per liter, accompanied by a price of BGN 2.50 per liter of gasoline.

March's fuel prices triggered protest marches of drivers all over Bulgaria, while the Commission on Protection of Competition (CPC) launched a cartel probe in the sector.

The result of the check failed to find evidence of a cartel agreement on the fuel market.

The turmoil caused by expensive fuel caused the Bulgarian center-right government to sign an agreement with Lukoil for a one-month moratorium on retail prices.

The fuel distributor, which controls 29% of the retail fuel market, froze gasoline prices at BGN 2.36 per liter and diesel at BGN 2.45 at filling stations of its chain.

The moratorium, originally set to expire on April 23, was subsequently extended to May 09.

The agreement for the price freeze aroused suspicions of very close ties between Bulgaria's Prime Minister Boyko Borisov and the head of Lukoil Bulgaria Valentin Zlatev, whom the opposition has described as "the country's back seat ruler" and "the oil oligarch, who pulls the strings of the government".