Bangkok - Thailand's King Bhumibol Adulyadej, the world's longest reigning monarch, who has been in hospital since mid-September, appeared in public Monday to partake in the kingdom's centuries-old Loy Krathong festival.

Amid family members and a cheering public, Bhumibol, 81, appeared outside Bangkok's Siriraj Hospital in an electric wheelchair to place a decorated krathong float into the Chao Phraya River, the River of Kings.

The Loy Krathong festival has been celebrated in Thailand since the 13th century.

Of Bhraman origin, the festival involves placing a decorated float, traditionally made of a banana tree stump but now usually of styrofoam, into a river or stream to let in "loy," or "float," away with one's wishes to the sea where the Hindu God Vishnu resides.

In Thailand, the king's public appearance was a wish come true for many.

He was admitted to Siriraj Hospital on September 19 to be treated for inflammation of the lungs. His recovery has been slow and a cause of worry for the populace, for whom the king has been a source of stability and continuity over the past
63 years of his reign.

He last appeared in public on October 23 to pay respects to a statue of king Chulalongkorn, his ancestor.

Bhumibol, who turns 82 on December 5, has been hospitalized on several occasions over the past decade to receive treatment for heart ailments and fever.

The king's latest illness came at a time when the country is reeling from a deep political divide with the established political elite trying to come to terms with new forces of populist politics and an empowered rural poor whose hero is ousted premier Thaksin Shinawatra.

Rumours that the king was seriously sick made the stock market plunge 7 per cent from October 14 to 15 although the panic was later found to be caused by unfounded rumours.

Two Thai stock brokers were arrested over the weekend on charges of violating the Computer Act for posting the rumours on websites deemed critical of the monarchy.

The royal family has indicated that Bhumibol would leave the hospital soon. (dpa)