BENGALURU, April 30 (Reuters) - India's Reliance Industries said on Friday its quarterly profit doubled, led by a rebound in its petrochemicals and retail businesses, but fell short of analysts' estimates as costs jumped 10%.

The oil-to-telecoms conglomerate, led by billionaire Mukesh Ambani, said consolidated profit climbed 108% to 132.27 billion rupees ($1.79 billion) in the three months to March 31. Analysts on average had expected 134.91 billion rupees, according to Refinitiv data.

Revenue at Reliance's oil-to-chemicals unit – home to both its refining and petrochemicals operations – rose 4.5% in the March quarter. The Mumbai-headquartered company benefited from pent-up demand globally for petrochemical products like PVC plastics, as business activity began to pick up after a coronavirus-hit 2020.

Reliance has built leading businesses in telecom and retail in recent years to diversify away from its mainstay energy arm, which has been recovering slowly from a coronavirus-driven slump in demand.

Its retail business of more than 12,000 stores and supermarkets posted a 20% jump in revenue as shoppers bought more groceries and apparel, resulting in all-time high revenues in those two categories, Reliance said.

Still, India's ongoing massive second wave of the virus, which has spurred lockdowns in many cities, had hit footfalls at stores as well as consumer sentiment, it said.

Revenues at Reliance's telecoms and digital unit Jio, which has been locked in a close battle with Bharti Airtel for subscribers, also jumped about 19%.

Overall, revenue edged up 11% to 1.55 trillion rupees.

Expenses rose 9.8% to 1.43 trillion rupees.

($1 = 73.9750 Indian rupees) (Reporting by Sachin Ravikumar in Bengaluru; Editing by Sriraj Kalluvila and Shailesh Kuber)