LONDON - Britain's Prince William is to marry his long-term girlfriend Kate Middleton next year, Buckingham Palace said on Tuesday, ending months of media speculation about the couple's plans to wed.

Britain's Prince William walks with his girlfriend Kate Middleton at RAF Cranwell in this April 11, 2008 file photo. [Photo/Agencies]

William, 28, the elder son of heir-to-the-throne Prince Charles and the late Princess Diana, and Middleton, 28, daughter of self-made entrepreneurs, became engaged while on holiday in Kenya last month.

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"The Prince of Wales is delighted to announce the engagement of Prince William to Miss Catherine Middleton," Charles's office said in a statement.

"The wedding will take place in the spring or summer of 2011, in London. Further details about the wedding day will be announced in due course."

The statement said William had informed Queen Elizabeth and also sought the permission of Middleton's father.

The Queen and William's grandfather, Prince Philip, said they were delighted at the news, while a cabinet meeting held by Prime Minister David Cameron was interrupted by a call from Buckingham Palace with the announcement.

"The prime minister is delighted to hear the news and has passed on his best wishes to the happy couple," Cameron's spokesman said.

William, who is currently serving as a helicopter search-and-rescue pilot in the Royal Air Force, met Middleton when they shared a house at university in Scotland in 2001.

They split up in 2007 because, newspapers said, Middleton, who has been dubbed "waity Katie" by the British tabloid press, was getting fed up of waiting for William to propose, but they soon got back together.

William has previously said he did not want to get married until he was 28, an age he reached in June.

Following the wedding, the couple will live in North Wales so the prince can continue his service with the RAF.

The engagement has been long predicted and rumours have abounded for months that an announcement was imminent.