Yangon, Aug 11 (DPA) A Myanmar court Tuesday sentenced opposition leader Aung San Suu Kyi to three years in prison and hard labour, but the sentence was immediately commuted to 18 months under house detention by the country's military supremo.

A special court set up in Insein Prison found Suu Kyi, 64, guilty of breaking the terms of her detention by allowing a US national to swim into her lakeside compound-cum-prison May 3, sentencing her to three years in prison with hard labour.

The same court found Suu Kyi's two house assistants guilty and sentenced them to three years in prison. It also sentenced US national John William Yettaw to seven years in jail for two visa violations and swimming without permission in Inya Lake.

Shortly after judges read their verdicts, Myanmar's Home Minister Maung Maung Oo announced to the court that junta chief Senior General Than Shwe had decided to commute Suu Kyi's sentence to one-and-a-half years under detention in her family compound in Yangon.

In a statement, Than Shwe said he had lessened Suu Kyi's sentence because she was the daughter of Myanmar independence hero General Aung San, to preserve peace and stability in the country and to assure that Myanmar goes along its 'democratic path'.

The 18-month sentence will assure that Suu Kyi is not free during the period leading up to Myanmar's planned general election next year, probably in May.

'I felt bad about the trial but did not want to interfere with the legal process,' Than Shwe said in his message.

He set several conditions on Suu Kyi's detention, including that she must remain within the house, but allowed her to write letters and watch state-run TV. If she abides by the conditions, Than Shwe said Suu Kyi might be quickly pardoned.

Her two house servants also had their sentences commuted to 18 months by Than Shwe.

Myanmar journalists representing foreign media were invited to attend the court session Tuesday morning at the last moment, raising expectations of some form of leniency.