BHP chairman steps down after Samarco delayed retirement

* CEO says aspirational goal for "gender balance" at all levels

* Chairman led push for productivity, efficiency

* Samarco victims stage protest (Adds comment from Nasser, CEO, context)

By Barbara Lewis

LONDON, Oct (HKSE: 3366-OL.HK - news) 20 (Reuters) - BHP Billiton Chairman Jac Nasser will not seek re-election at next year's annual general meeting, he announced on Thursday, saying after 10 years at the top and overseeing the initial response to the Samarco dam disaster, it was time to retire.

Nasser said he had intended to resign last year but agreed to stay on at the world's biggest miner to provide stability as BHP responded to the disaster in Brazil.

Now (Frankfurt: 11N.F - news) the "basic structure of the Samarco response is in place," Nasser said in a speech at this year's Annual General Meeting (AGM), he would not seek re-election, but would carry on leading the board in the interim.

BHP's Chief Executive Andrew Mackenzie in a separate speech said the company had set a 2025 goal of achieving "gender balance at all levels of the organisation over the next decade".

The 12-strong board has three women members.

Mackenzie declined to be drawn on whether there might be any particular considerations in deciding the new chairman, saying the board was engaged in an ongoing succession process.

Asked whether the new chairman might be a chairwoman, Nasser said "why not?" but he would not insist on a woman, adding changing the gender balance would take time.

As someone who grew up in the northern suburbs of Melbourne, Australia, Nasser, 68, said he had never expected to lead global companies.

He was named chairman of BHP in August 2009 and had joined the board as non-executive director in 2006.

Before that, he was CEO of Ford, where his reputation as a cost-cutter earned him the nickname "Jac the Knife".

At BHP, Nasser experienced the China-led commodities boom and the bust, which the company had weathered better than peers, he said.

"We kept a solid A credit rating through the valley of the commodity price death," he said.

BHP had been ahead in enforcing a shift away from unfettered spending to a focus on productivity and efficiency, he added.

Nasser said he hadn't given much thought to what he would do next, but it was the right time to move.

"Whenever you join a board, I think you always have some timeframe in mind. My timeframe was in the order of 9 to 10 years," he said.

His last year has been what he described as "one of the most challenging periods" in BHP's history, largely because of the Samarco dam burst in which 19 people died. Samarco is a 50/50 joint venture between BHP and Brazil's Vale.

Brazilians impacted by what Brazil says is its worst environmental disaster were among those who staged a protest outside Thursday's AGM in central London.

Mackenzie said the company was working flat out to rectify the damage and compensate those affected. (Additional reporting by Mamidipudi Soumithri in Bengaluru; Editing by David Goodman and David Evans)