Brazil's mining giant Vale said on Wednesday that Aquila Resources Ltd's latest moves could eventually lead to delays and frustrations on their joint coal project in Queensland as managing director Decio Amaral emphasised that the company merely wants to proceed with the feasibility study it is proposing.

The feasibility study is the latest issue nagging the joint partnership with Aquila earlier filing a suit against Vale for some infrastructure disagreements, with now some mere wording of conditions for a feasibility study again hampering their ongoing joint venture.

Mr Amaral said that "Aquila's refusal to agree to pass the budget resolution with respect to certain capex items which we accepted may unfortunately cause delay, frustration and unnecessary uncertainty," as he noted that Bowen Central Coal (BCC), Vale subsidiary, has already issued a notice of dispute on Friday last week regarding the matter.

Aquila said on Tuesday that the feasibility study should clearly consider port and rail logistics of the Eagle Downs project as the company sought to make commitments to the Abbot Point coal terminal while Vale wanted to commit future capacity at the Dalrymple Bay coal terminal.

On the other hand, Vale raised some questions on the accuracy of Aquila's released statement on Tuesday, accusing its partner of attempting to enmesh the budget approval condition.

Vale has maintained that "Aquila has sought to add words to the budget approval condition, which BCC does not accept are either necessary or accord with the terms of the JVA and which, in BCC's opinion, are not a mere 'clarification'."

Still, the market seemed to have sided with Aquila on the issue as its stocks gained a bit and as of 1159 AEST, Aquila shares were trading at $8.93, increasing by 30 cents or 3.48 percent.