The Australian High Court ruled in favour of mining workers this week and threw out a Rio Tinto appeal that requests for the reversal of an earlier decision that requires the giant mining firm to honour collective bargaining agreements.

ABC reported on Saturday the High Court ruling, which upheld the Federal Court's stance that collective bargaining cannot be supplanted by side deals with specific groups of Rio Tinto's workers deployed on its iron ore mining operations in Pilbara.

"The union successfully argued that that agreement was invalid, the High Court refused to hear an appeal against that, and that means that it's open to those workers and their union to seek a collective agreement in the future," Professor Andrew Stewart of the University of Adelaide told ABC on Saturday.

Stewart noted that prior to the legal case, Rio Tinto has been working on the acceptability of its deals with mining workers, which he noted were intended to replace the bargaining agreements that were normally accorded to employees.

With the decision, the High Court has declared that companies cannot work their way around on important components of Australian labour environment, Stewart added.

As many as 5000 workers toiling for Rio Tinto in the Pilbara region will benefit from the decision, media reports said.

Stewart also noted that that High Court ruling will impact a similar case being waged by another mining giant, BHP Billiton, which earlier this week has reported another record half year.

"It makes it harder to shut unions out of that particular part of the mining industry," Stewart said.

In a statement, Construction, Forestry, Mining and Energy Union (CFMEU) hailed the High Court decision, with the labour group's mining division chief, Andrew Vickers, declaring that once and for all, Rio Tinto was put in line on how to legally deal with the workers that keep the company running.

"It puts to rest the fallacy perpetrated by Rio Tinto and their lawyers that they put in place a valid non-union agreement with a small group of workers in their Pilbara iron operations and then extended that agreement effectively to all employees," Vickers said.

Analysts view the legal development as mostly defining on the future relationship between companies and workers and whether the latter can employ the High Court ruling in further improving their working conditions and benefits.