Muslims attend Friday prayers during the second day of Ramadan, in the courtyard of a housing estate next to the small BBC community centre and mosque in east London                           ( Reuters

The UK's big supermarkets are expecting a £100m (€140m, $158m) boost to their grocery sales over the next month due to the holy month of Ramadan, The Times reported.

Three million Muslims in the UK break their fast with often lavish sundown meals during the holy month, commemorating the first revelation of the Koran to Prophet Muhammad.

Retailers are increasingly capitalising on the opportunity, and they say that the religious festival is now the third most important for them after Christmas and Easter.

Meat, rice and fruit have emerged as the big sellers during the fasting season, according to the retailers.

Morrisons is expected to sell more than two million tons of rice, while Sainsbury's expects rice sales to increase at least 100 percent year on year. Rival Tesco expects a £30m boost to its sales during the month.

Sainsbury's is running a promotional event for Ramadan in 270 stores until 21 July, while Tesco has sales promotions at more than 300 stores in the UK.

"In terms of religious festivals, Ramadan is second now to Christmas and Easter in its importance to food retailers," George Scott from retail consultancy Conlumino, was quoted as saying by The Times.

"It's very lucrative. It's a growing market because the country is becoming more diverse - and if the supermarkets want to win customers, they have to cater to every taste."

During Ramadan, which started on 18 June and will end on 17 July, Muslims are forbidden from eating and drinking from sunrise to sunset. The expected higher retail sales mean that Muslims are stocking up on products to break their daily fast at sundown.