Mining activities on seven Queensland coal mine sites owned and operated by BHP Billiton virtually ground to a halt on Wednesday as workers stopped toiling to commence what could become the nation's biggest industrial disruption in years.

According to Agence France Presse (AFP), mine workers aligned with three major labour unions - the Construction, Forestry, Mining and Energy Union (CFMEU), Australian Manufacturing Workers Union (AMWU) and the Communications, Electrical and Plumbing Union (CEPU) - joined the synchronised work stoppage that swelled the ranks of striking workers to 3500.

Workers, according to union representatives, were fighting for better working conditions, higher pays, housing and health benefits, negotiations of which to secure them have dragged for more than a year.

CFMEU district president Stephen Smyth told AFP that this would be the first time that the mining sites' operations would be crippled by a massive and coordinated industrial action.

The Queensland mining sites are one the world's major source of coking coal and is jointly operated by BHP Billiton and its Japanese partner Mitsubishi under BHP Billiton Mitsubishi Alliance (BMA).

Workers claimed that the mines operations have largely contributed to the huge profits raked in by BHP, currently the biggest mining firm in the world and a global leader in the production of iron ore, coal and other minerals that feed the industrial development of many nations.

CFMEU National President Tony Maher firmly believes that BHP is more than capable of giving the demands laid out by workers, judging from its recent financial reports that outlined succeeding record profits.

"Last year, BHP made a record $23 billion profit. These workers are taking a stand for safe, secure jobs ... and BHP can afford to do the right thing," Maher told AFP.

That was followed by another rosy figure this year when the miner reported that it achieved more than $9 billion in profits for the first half of financial year 2011-2012, with notes that the company actually saw a considerable slide.

The slide, however, was offset by the fact that BHP's profits represented the biggest gains in Australia, with BHP CEO Marius Kloppers even indicating last week that despite the weakening demands and other challenges, the company is gearing for multi-billion expansions in the years ahead.

Analysts warned that the production issues encountered by BHP during the Queensland floods in early 2011 may again affect its output goal for the current fiscal year if the industrial disputes will not be resolved early.

In a statement, BHP did not touch on the impact of the strikes to its overall coal production in Queensland but the company reiterated its intent to settle the labour issues at hand.

"We reserve the right to manage our business safely and in a commercially successful way, and we're urging employees and representatives to return to constructive discussions," AFP reported BHP as saying.

"We're disappointed with any decision to stop work, but we remain committed to resuming negotiations in good faith. We just really want to get back to the negotiating table," the company stressed.