* Brotherhood leader says secular groups need to organise
* Islamist says self-imposed restrictions are temporary
* Says idea of broad election coalition under discussion
By Tom Perry
CAIRO, March 23 (Reuters) - The Muslim Brotherhood is not planning to seek power in Egypt's elections this year but says it will not limit its political ambitions forever and wants secular parties to get organised to foster true competition.
"Everyone must act so we can reach the point where we become like the rest of the countries in the world, with three or four strong parties," said Mohamed el-Beltagi, a Brotherhood leader.
"The others have been slow to move," he said, referring to secular activists with whom the Brotherhood joined forces in mass protests that toppled Mubarak, helping ignite revolts in other Arab countries now watching the pace of change in Egypt.
The Brotherhood, founded in 1928, has emerged from decades of oppression as Egypt's best-organised political group, causing concern among secularists over the Islamists' political role in one of the Arab world's most influential countries.
Anxious to reassure other Egyptians, the Brotherhood has said it will seek neither the presidency nor a parliamentary majority in elections which the military rulers to whom Mubarak handed power have pencilled in for September.
But Beltagi said: "We will not forever remain in the position of not seeking power, the majority or the presidency. This is a temporary position until the time there are forces that can compete. At that point, we will take part in the competition."
After years of rigged elections, there is no way to accurately gauge the popularity of the Brotherhood, which was banned under Mubarak but allowed to operate within limits.
Since he was deposed, the Brotherhood has moved to the heart of public life. It always posed the main opposition challenge in elections, but only a fraction of Egyptians ever took part in voting that was rigged in favour of Mubarak. This year's elections are expected to draw millions of new voters.
"We are talking about participation and not domination," said Beltagi.
Across the region, he sees a future for Islamist movements as part of political life but not dominating it. Secular nationalists, leftists and liberals should emerge, said Beltagi.
"If the Islamic trend tries to become dominant in positions of authority, we could encounter big problems.
"If the other forces strive to block or censor the Islamic trend we will encounter a bigger problem," he added, recalling the war that erupted in Algeria in 1991 when elections that seemed likely to produce an Islamist victory were cancelled.
A doctor, Beltagi, 47, is typical of a Brotherhood leadership largely drawn from professional, middle class Egyptians. He was 16 when he joined the group, which managed to survive security crackdowns under Mubarak.
Brotherhood leaders have said the group will run for about a third or more of the seats in parliament and not contest the presidential election expected in December or later.
The group's priorities will be political reform, guaranteeing public and political freedoms, social justice and restoring Egypt's regional influence, Beltagi said.
"We support a substantial reduction in the powers of the president of the republic."
Asked about the role of Islamic law in shaping the group's political agenda, he said: "This is all in line with sharia and is not at odds with sharia, but it is not a question of sharia."
For the legislative elections, Beltagi said the group was discussing the idea of forming a single country-wide list with other reformists. The proposal would aim to produce "a national revolutionary majority", he said.
But in recent weeks, the Brotherhood has found itself increasingly at odds with other, mainly secular sections of the Egyptian reform movement that coalesced to topple Mubarak.
The disagreement has focused on the political transition set out by interim military rulers. The groups fell out publicly over a referendum on constitutional changes which was passed by a big majority at the weekend.
The Brotherhood has been accused of mobilising religious influence to support its campaign for a "yes" vote. It denies that assertion but Beltagi says other Islamic groups and figures had invoked religion in the campaign in favour of the changes.
"From our point of view, the matter was a political thing that had nothing to do with heaven and hell," he said.
Editing by Mark Heinrich