Myanmar may have freed all political prisoners - opposition

YANGON (Reuters) - Myanmar may have released all of its remaining political prisoners in an amnesty for 514 detainees on Monday, its main opposition party said, just over a week ahead of a rare visit by its reformist president to the United States.

"We're optimistic that these are the remaining political prisoners," said Naing Naing, a central executive committee member of Aung San Suu Kyi's National League for Democracy (NLD) party.

The timing of the amnesty issued by President Thein Sein could accelerate the pace of reforms in the former military-run state and strengthen its growing bonds with the United States, which has called for the freeing of all remaining dissidents as a pre-condition for any further economic rewards after easing some sanctions this year.

Naing Naing said he understood 424 political detainees were freed in the amnesty. That figure would exclude inmates who were former military intelligence officials purged under the former junta.

Thein Sein, whose government released nearly 700 political prisoners between May 2011 and July this year, was due to head to the United States on September 24, where he will address the U.N. General Assembly in New York for the first time as president.

He is expected to use the event as a platform to showcase his government's reforms, attract much-needed aid and investment and try to convince the international community to lift all remaining sanctions, in particular, import bans on Myanmar-made products.

Opposition leader Suu Kyi, the Nobel Peace Prize laureate and pro-democracy champion, left on Sunday for the United States where she will receive a Congressional medal.

While Suu Kyi is due to meet U.S. President Barack Obama, it is not known whether Thein Sein will.

Thein Sein will be allowed to venture outside the relatively small confines of U.N. territory for the first time after Washington issued a waiver on visa restrictions in its latest concession towards Myanmar.

Most Western sanctions on Myanmar, which was ruled for 49 years by an authoritarian junta, have been suspended since April in recognition of its political, economic and social reforms.

Washington has eased some embargoes in the past few months, including some covering investment, but the Senate Finance Committee opted in July to extend a ban on Burmese imports to maintain pressure on the government to reform.

Myanmar wants that to be lifted, as well as similar restrictions by the European Union, in order to attract foreign firms to the country to set up manufacturing operations and create urgently needed jobs for a population that is among Asia's poorest.

Monday's amnesty came as the New York-based Human Rights Watch reiterated calls for political prisoners to be released, accusing the government of "dragging its feet rather than fulfilling its promises".

(Writing by Martin Petty; Editing by Nick Macfie)