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AMSTERDAM, Jan 28 (Reuters) - Dutch Queen Beatrix, who turns 75 on Thursday, is expected to announce her abdication in favour of her son, Prince Willem-Alexander, in a hastily announced broadcast to the nation on Monday evening, Dutch media reported.

The address, scheduled for 7 p.m. (1800 GMT), was announced by the Royal Household, but no further details were released.

Queen Beatrix became the sixth monarch of the House of Orange in 1980 following the abdication of her mother, Queen Juliana, who reigned for 31 years.

Juliana was 73 years old and in deteriorating mental health when she abdicated but Beatrix has remained active and in good health despite some setbacks.

The queen was emotionally shaken when a man drove his car into a Queen's Day procession in 2009.

Her middle son, Prince Johan Friso, has been in a coma ever since he was buried in an avalanche while skiing last year. (Reporting by Sara Webb and Anthony Deutsch; Editing by Robin Pomeroy)

Earlier on HuffPost:

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  • Dutch Queen Beatrix and her daughter in-law Princess Mabel, right, arrive at the hotel where the Dutch Royal family stay in Lech, western Austria, Saturday, Feb 18, 2012, the day after Beatrix 2nd son, Prince Johan Friso, was rushed to the intensive care unit of Innsbruck's main hospital after he was buried by an avalanche. (AP Photo/Dietmar Stiplovsek)

  • Dutch Queen Beatrix and her daughter in-law Princess Mabel, right, arrive at the hospital in Innsbruck, western Austria, Saturday, Feb 18, 2012, the day after Prince Johan Friso was rushed to the intensive care unit of Innsbruck's main hospital after he was buried by an avalanche. (AP Photo/Kerstin Joensson)

  • Dutch Queen Beatrix and her daughter in-law Princess Mabel, right, leave the hospital in Innsbruck, western Austria, Saturday, Feb 18, 2012, the day after Beatrix 2nd son, Prince Johan Friso, was rushed to the intensive care unit of Innsbruck's main hospital after he was buried by an avalanche. (AP Photo/Kerstin Joensson)

  • Dutch Queen Beatrix and her daughter in-law Princess Mabel, right, arrive at the hospital in Innsbruck, western Austria, Saturday, Feb 18, 2012, the day after Prince Johan Friso was rushed to the intensive care unit of Innsbruck's main hospital after he was buried by an avalanche. (AP Photo/Kerstin Joensson)

  • Outside view of Hotel Post in the skiing resort of Lech, western Austria, Saturday, Feb. 18, 2012, where the Dutch Royal family spend their winter holidays. Prince Johan Friso, the second son of Dutch Queen Beatrix, is being treated at the intensive care unit of a hospital in Innsbruck after an avalanche buried and seriously injured him while he skied off marked trails Friday in Lech. (AP Photo/Dietmar Stiplovsek)

  • View of the skiing resort of Lech, western Austria, Saturday, Feb. 18, 2012, where the Dutch Royal family spend their winter holidays. Prince Johan Friso, the second son of Dutch Queen Beatrix, is being treated at the intensive care unit of a hospital in Innsbruck after an avalanche buried and seriously injured him as he skied off marked trails Friday in Lech. (AP Photo/Dietmar Stiplovsek)

  • A sign shows the way to the university hospital in Innsbruck, western Austria, Saturday, Feb. 18, 2012. Prince Johan Friso, the second son of Dutch Queen Beatrix, is being treated at the intensive care unit of the hospital after an avalanche buried and seriously injured him while he skied off the trail Friday in the westernmost corner of Austria. (AP Photo/Kerstin Joensson)

  • In this Feb. 19, 2011 file photo Netherland's Prince Friso, left, and his wife Princess Mabel, right, pose with their daughters Luana and Zaria for photographers during a photo session in the Austrian skiing resort of Lech. Dutch Prime Minister Mark Rutte and the Austria Press Agency say Queen Beatrix's second son Friso of the Dutch royal family has been hit by an avalanche in Austria. Austrian news agency APA reported Friday Prince Friso was buried under snow for 15 minutes before he was rescued and taken to a hospital in Innsbruck. The agency gave no source for its information and had no immediate information on Friso's condition. (AP Photo/Kerstin Joensson, File)