The new undertaking also addresses the process for parties to negotiate access to the rail network and how any disputes related to access can be resolved.

Delays in finalising access arrangements had led to a reduction in investment in the $11 billion Queensland export coal industry.

The Queensland Competition Authority rejected an earlier QR draft undertaking on rail access, prompting the company to take legal action against the regulator. The company later withdrew its case.

The regulator said the new undertaking provided for an average reduction of 17% in central Queensland coal tariffs and 20% in Western Sydney coal tariffs from the previous access regime, approved in 2001.

The authority said the central Queensland tariff reduction was smaller than foreshadowed in December last year due to three main reasons: a move from a five-year to a four-year regulatory period; an increase in the global capital expenditure provision; and a reduction in demand forecasts for 2005-06.

Key changes between the accepted access undertaking and the 2001 undertaking were said to include a master planning process to provide robust and transparent management of the future development of the central Queensland coal network.

The new agreement was also said to provide a more streamlined and certain process to establish new reference tariffs and standard access agreements.

In submissions on the latest access undertaking, the Queensland Resources Council and BHP Billiton-Mitsubishi Alliance clearly indicated the authority should support it.

Rail company Pacific National, meanwhile, argued the undertaking was too complex and the authority should have waited for a government review of the Queensland Competition Authority Act before approving it.