The figures come as the corporation has sought to save in the face of high inflation and a freeze on license fees, including plans for local radio stations to share more content and broadcast fewer programs unique to their areas.
BBC journalists have gone on strike to protest against the proposals, which also include the switch to digital for some World Service radio and television broadcasting services.
In its recent annual plan, the BBC stated that its savings target had increased by 40 per cent to £400 million.
Charlotte Moore, BBC chief content officer, said: “Radio 2 remains the country’s most popular station and I am delighted with the strong start Vernon Kay has made mid-morning as the UK’s biggest radio show, bringing his warmth, energy and charisma to listeners across the country.
“We have had an incredible summer of music and sport with record numbers at the Proms reflected by Radio 3 reaching over two million listeners with its unique commitment to live classical broadcasts.
“The Ashes, Wimbledon and the Women’s World Cup significantly boosted 5 Sports Extra, as well as delivering results for 5 Live and BBC Sounds.”
Sam Jackson, Controller of BBC Radio 3, added: “It is very encouraging to see that BBC Radio 3 reaches a weekly audience of over two million people, and that the station has welcomed around 300,0000 new listeners during this period.
“We have clearly attracted more listeners this summer, and we hope that those who have discovered the breadth of distinctive programming on Radio 3 will stay with us for the long term.”