Aung San Suu Kyi has been selected to continue as head of Burma's main opposition party, keeping her leadership post even as the party undergoes an overhaul to adjust to the country's new democratic framework.

The Nobel laureate was named chairwoman of the National League for Democracy's new executive board on the final day of a landmark three-day party congress attended by 894 delegates from around the country.

The congress also expanded the group's central executive committee from seven members to 15, in a reform effort ahead of Burma's 2015 general election. The party is seeking to infuse its ranks with new faces, expertise and diversity without sidelining longstanding members.

"We have to see how effectively and efficiently the new leaders can perform their duties," said Aung San Suu Kyi, who has led the NLD since its inception in 1988. "We hope they will learn through experience."

Aung San Suu Kyi's selection had been assured, since she is the party's main draw. But her dominant influence has also attracted criticism that the party may be too reliant on her charisma.

Asked about allegations by critics that the NDL leans toward an authoritarian structure, she said that "all our leaders have been elected democratically. So if they feel that they do not like authoritarian leadership, they should not vote for those whom they think are authoritarian."

Aung San Suu Kyi conceded that there has been some friction in the party's current transformation process, with complaints surfacing about lack of transparency and fairness in the election of local leaders in the runup to the congress. Four party members who had been elected to attend the congress were suspended just two days before it opened Friday over allegations of irregularities in their selection.

Aung San Suu Kyi is the sole survivor from the party's original executive board, but the other new members are also mostly long-serving party loyalists, disappointing some who were looking for new blood. A broader central committee of 120 members was elected by the delegates and endorsed the executive board, which was given five reserve members.

The NDL, which formed as the army was crushing a mass pro-democracy uprising in 1988, won a 1990 general election that was nullified by the then-ruling military. The party boycotted a 2010 general election, but after a military-backed elected government took office in 2011 and instituted democratic reforms, it contested byelections in 2012, winning 43 of 44 seats and putting Aung San Suu Kyi into parliament.

Emerging from repression that limited its actions – not least because Aung San Suu Kyi and other senior party members spent years under detention – the NLD leader vowed in her opening speech on Saturday to inject the party with "new blood" and decentralise decision-making processes.

She said the NLD would go through an experimental stage with the new leadership and should anticipate some obstacles but "not be discouraged".

Speaking to the party meeting after her selection as chairwoman on Sunday, Aung San Suu Kyi said that in choosing executive board members there was an effort to include women, members of ethnic minorities and younger people, in addition to members with a record of continuous party service. Four women and several ethnic minority members are on the new board.