New Delhi: Increase in fuel costs and impact of foreign exchange rate variation were two major reasons for Air India's operating loss of Rs 4,685 crore in 2018-19, Civil Aviation Minister Hardeep Singh Puri said on Thursday.

"Aviation Turbine Fuel (ATF) costs increased from Rs 7,363 crore in 2017-18 to Rs 10,034 crore in 2018-19 i.e. an increase of almost 28.9 per cent in fuel rates over the previous year," Puri said in a written reply to a question in Lok Sabha.

"The impact of exchange rate variation led to an increase in expenses from Rs 31 crore in 2017-18 to Rs 772 crore in 2018-19," he added.