Materials stocks were rising about 0.6% in midday trading on Monday, as almost all other sectors were in the red amid a continued blockade of the Strait of Hormuz.

Altair Minerals (ASX:ALR) shares surged 20% after it received a firm commitment from an Endeavour Mining subsidiary to raise AU$28.2 million through a placement of 656.3 million shares.

Meanwhile, energy stocks were leading broader declines with a fall of 1.7% even as oil prices edged higher.

Shares of Origin Energy (ASX:ORG) were down nearly 3% after it reported March quarter production of 164.5 petajoules, down from 167.1 petajoules a year earlier.