THE Duke of Edinburgh was said to be progressing satisfactorily last night after undergoing planned abdominal surgery at a private hospital in London.

Prince Philip had the operation under general anaesthetic after being admitted to the London Clinic in Harley Street on Thursday evening, hours after appearing at a garden party in Buckingham Palace with the Queen.

The procedure took place just days before the royal's birthday on Monday, when he will turn 92.

Buckingham Palace said the results of the operation would now be analysed.

In a short statement, the Palace said: "His Royal Highness the Duke of Edinburgh has had an exploratory operation following abdominal investigations. The results will now be analysed.

"At this early stage he is progressing satisfactorily."

The operation coincided with the official opening of the BBC's revamped headquarters at New Broadcasting House by the Queen, who pressed ahead with the engagement yesterday despite Prince Philip's latest health scare.

Peter Phillips, the Duke's eldest grandson, said the family were being kept informed about his grandfather's progress, and that he would not want them to miss engagements.

He said: "Obviously our thoughts and prayers are with him – we know that he's in good hands and we've been kept up-to-date in terms of what's happening.

"But he's one of those people who wouldn't want you to stop just because he's gone into hospital."

During her visit, the Queen gave a live broadcast on a BBC Radio 4 programme presented by James Naughtie and Sian Williams.

In her short address, heard across the globe via the World Service, she referred to a previous visit to Broadcasting House with her husband shortly before her coronation 60 years ago.

She said: "I remember first coming to Broadcasting House with my father the King and my mother and sister shortly before the war.

"I came again with the Duke of Edinburgh shortly before the coronation in 1953."

She added: "I hope this new building will serve you well for the future and I am delighted to declare it open today."

The Queen looked relaxed and at ease during her visit and appeared to enjoy meeting the famous faces, from news presenters Sophie Raworth and Huw Edwards to Sir Bruce Forsyth, David Dimbleby and Professor Mary Beard.

Sir Bruce said it was a "great shame" the Duke could not attend the opening.

Actress Jenny Agutter added: "I think the Queen coming here shows that she can do it on her own, she's done that before, but she was prepared to come without her consort."

The Queen was taken on an extensive tour of the revamped Broadcasting House. In the newsroom she was besieged by staff who held up their camera-phones and cheered and waved as she walked past their desks.

Prince Philip faces up to two weeks in hospital as he recovers from the operation – his third hospital admittance in 12 months.