LIkely it will take a while to get all the T's and C's ticked off, especially if the ACCC puts conditions on the acquisitions. If they block, Qantas will likely to go to the National Competition Tribunal to overrule the ACCC. I expect that the mining companies will do their best to either extract significant concessions from Qantas or possibly block it, unless they can find another way to get some competitive tension. Rio Tinto particularly is at risk of ending up with Qantas holding most of its charter/RPT contracts, and they will want to ensure there is some competition in the market.