India’s gasoline and diesel sales during the first half of July dropped from last month as seasonal rains curtailed demand in the world’s third-biggest energy consumer, that could help keep a lid on oil prices.

The three biggest retailers sold 1.28 million tons of gasoline during July 1-15, down about 8% from the corresponding period in June, according to refinery officials with knowledge of the matter. Diesel sales fell almost 14% from last month, said the people, who asked not to be identified discussing unpublished data.

The retracement in India’s fuel demand adds pressure on the price of oil amid rising pessimism about a global economic slowdown that dragged it below $100 a barrel for the first time since early April. The softening of demand could also add to a supply glut in the region that’s curtailing the profits from processing gasoline and diesel.

This is the first monthly decline in sales in three months after resurgent economic activity, summer travel and increased use of diesel-fired generators during a severe heat-wave drove the South Asian nation’s fuel demand.

Fuel consumption in India typically declines in this time of the year because of the monsoon rains that lasts till September. It hampers trucking and construction activities, weighing on demand for diesel, the country’s most-used petroleum fuel.

India has so far received 13% higher than normal rains during the current monsoon season rainfall, according to data published by the India Meteorological Department on July 17.

Sales of liquefied petroleum gas, a cooking fuel, rose 8.3% from June, while aviation fuel fell 6.7%.

Spokespeople at the three retailers -- Indian Oil Corp., Bharat Petroleum Corp. and Hindustan Petroleum Corp. -- couldn’t immediately comment. The companies together account for over 90% of Indian fuel sales.