YANGON, (Reuters)April 3 — Myanmar's pro-democracy opposition says talks between Nobel Peace Prize winner Aung San Suu Kyi and the junta are taking too long and yielding too little but has promised patience to keep them going.

In an interview late on Wednesday, National League for Democracy (NLD) Secretary U Lwin denied speculation his party would pull out of the U.N.-brokered talks if Suu Kyi was not freed soon from house arrest by the ruling military.

''People say we're getting frustrated, but we have enough patience to wait. For us there's no way out, we have to keep going,'' U Lwin told Reuters in his party's ramshackle Yangon shop-house headquarters.

''In order to make progress in dialogue, it depends on both sides. But when there is an empty chair on the other side, what can you do?''

''Reconciliation is going on and communication has been established. We always have contact, and sometimes there's progress...it's too little, taking too long (a) time.''

The talks, which began in late 2000, have yielded the release of more than 250 political prisoners and some freedom for the NLD to operate, but have not broached political change.

Another senior NLD official, who asked not to be identified, said on Thursday the two sides had yet to start a real dialogue and were still ''confidence building.'' ''There must be an advance to a new stage. Dialogue means that anything can be put on the table,'' he said, adding that ethnic minority groups also needed to be involved in the process.

The NLD wants its leader Suu Kyi freed from house arrest and the release of 1,500-1,600 political prisoners, including up to 650 party members. The NLD members include 17 elected NLD politicians who have languished in jails since the early 1990s.

NO PRECONDITIONS

The NLD source said the party and Suu Kyi were ready for dialogue at any time and had not set preconditions, but the military should show sincerity by freeing all political prisoners, including Suu Kyi, and let the NLD operate freely.

He said Suu Kyi, as head of the NLD, should lead the dialogue from its side. He said she remained optimistic, ''but she wishes to be free as soon as possible so she can resume the legitimate activities of a free political party.''

The NLD, whose leaders include several ageing former ministers such as U Lwin, swept Myanmar's last democratic elections in 1990 by a landslide but has never been allowed to rule. The United States, European Union and other Western nations are likely to consider toughening trade and aid sanctions on the impoverished Southeast Asian nation if talks completely unravel.

U.N. envoy Razali Ismail is due to visit Myanmar on April 22 in a bid to move the process forward, having had a trip last month put off by the government. The junta said it was too busy dealing with an alleged coup attempt by relatives of Ne Win, who ruled Myanmar with an iron fist from 1962 to 1988. In early March, Ne Win and his daughter were put under house arrest, and his son-in-law and three grandsons were arrested on the charge of high treason, which carries the death penalty.Three high-ranking military officers were also arrested and over 100 others have been interrogated in connection with the alleged plot, which authorities said also involved an astrologer dabbling in black magic.

But many diplomats are sceptical a coup was being planned and say the clampdown was really an attempt by junta leader Than Shwe to root out potential opponents. A strengthened Than Shwe is unlikely to loosen his grip on power, they say. U Lwin said the move against the unpopular Ne Win clan could give the regime to move ahead with political change.

''NO PERMANENT ENEMY''

''If I was on the other side, the time is appropriate since the departure from the old man's influence,'' U Lwin, who was a finance minister under Ne Win in the 1970s before falling out of favour, said referring to his former boss. ''There's no permanent enemy or permanent friend in politics and we can forget easily. It's about time to cooperate towards the betterment of society.''

Diplomats say the party now wants to work with the government, especially on social and humanitarian issues, but would shy away from power-sharing with a regime that has led the country into economic ruin.

Some analysts say the NLD will walk away from the talks if the junta does not make serious concessions soon. But U Lwin said the NLD risked political limbo if it did not stay engaged. ''Although we're the opposition, we're responsible for bringing happiness and prosperity to the people. If we're impatient or can't control emotions and anger, who will suffer? The people.''

(With additional reporting by David Brunnstrom)