IRONORE/ Sector giants BHP BHP.AX, Rio Tinto RIO.AX and Fortescue Metals Group FMG.AX advanced between 0.3% and 2.8%, respectively. By Roushni Nair May 30 - Australian shares ended at a more than three-week high on Monday, led by gains in commodity stocks and technology firms tracking a Wall Street rally, though AGL Energy tumbled after shelving its demerger plan. Leading gains, tech stocks .AXIJ rallied 4.6%, a three-week high after U.S. peers jumped on Friday on optimism about a stable economy on signs of peaking inflation and consumer resiliency.