Sluggish demand from the manufacturing and aerospace industries has depressed aluminium prices, the firm said.

Alcoa posted net income of $232m for the second quarter, slightly below expectations, sending the firm's shares down slightly in early New York trading.

Alcoa has suffered a series of bleak quarters, and its shares have lost more than 12% of their value this year.

Aluminium prices have risen about 10.5% from November's low, but remain 5% below their levels of a year ago.

To offset the low prices, Alcoa has slashed costs and claims to be on track for annualised savings of $1bn next year.