Mineral Resources has delivered its Chinese rival what it hopes will be a knockout blow in the race to acquire oil and gas producer AWE but the $526 million agreed takeover deal has left some investors questioning whether a higher price could have been achieved.

The offer from the mining services provider led by Rich Lister Chris Ellison has been improved with a cash alternative and values the target at about 83¢ a share, almost 14 per cent higher than the all-cash proposal from China Energy Reserve and Chemicals Group.