New Delhi: Petrol and diesel prices were on Monday slashed by Rs 2 per litre each as international oil prices slumped to a five-year low.

This is the eighth straight reduction in petrol prices since August, and the fourth straight in diesel since October. New rates will be effective from the midnight of December 15 and 16, Indian Oil Corp, the country's largest fuel retailer, announced here.

In Delhi, petrol will cost Rs 61.33 a litre - the lowest in 44 months - as compared to the current price of Rs 63.33. The price has been cut by Rs 2.09 a litre in Mumbai to Rs 68.86.

Rates differ from state to state because of varied rates of local sales tax or VAT.

Diesel will cost Rs 50.51 a litre in Delhi - the lowest since July 2013 - as against Rs 52.51 currently. In Mumbai, it will cost Rs 57.91 per litre as compared to Rs 60.11.

The prices of petrol and diesel were last revised downwards on December 1 by 91 paise per litre and 84 paise per litre, respectively, (including state levies at Delhi) on the back of declining international oil prices.

After Monday's reduction, petrol price has been cut by a cumulative Rs 12.27 per litre since August.

Diesel price was brought down for the first time in more than five years on October 19 by Rs 3.37 a litre when the government decided to deregulate the fuel. This was followed by a Rs 2.25 a litre reduction on November 1 and 84 paise per litre on December 1.

Cumulatively, diesel prices have been cut by Rs 8.46 a litre in four reductions.

There would have been another reduction on November 15 but the government mopped up, raising excise duty on petrol and diesel by Rs 1.50 a litre each.

In the two excise duty hikes, the government has raised its revenue by Rs 10,600 crore this fiscal year.

"The prices of petrol and diesel were last revised downwards with effect from December 1 by Rs 0.91 per litre and Rs 0.84 a litre respectively (including state levies at Delhi) on the back of declining international oil prices," Indian Oil said in a statement.

"Since the above price changes, the international prices of both petrol and diesel have continued to be on a downtrend. The Rupee-US Dollar exchange rate has however appreciated since the last price change. The combined impact of both these factors warrant a decrease in retail selling prices of both petrol and diesel."

The movement of prices in international oil market and rupee-dollar exchange rate shall continue to be closely monitored and developing trends of the market will be reflected in future price changes, it added.