The new machine weighs more than three jumbo jets

The continuous steel slab caster, which was unveiled on Wednesday, is said to weigh more than three jumbo jets.

Corus said the machine would increase the plant's annual output of steel slab by a quarter.

It will mean Corus will be able to supply slab from Port Talbot, rather than having to ship it from Teesside.

"The investment will significantly improve the competitiveness of Corus' UK carbon steel assets," the group said in a statement.

The new steel-caster is part of a �210m programme of investment in Wales by Corus over the last three years.

The Port Talbot plant's number five furnace was completely rebuilt at a cost of �75m after a 2001 explosion in which three workers died 12 workers were injured.

Jobs lost

Corus was created in 1999 by the merger of British Steel and Dutch firm Koninklijke Hoogovens.

Restructuring of its operation saw 13,000 jobs lost across its British plants, which include bases at Port Talbot, Scunthorpe and Rotherham.

In Wales alone, 3,000 jobs were axed and plants at Ebbw Vale and Gorseinon were shut.

The firm, which has more than 48,000 employees in more than 40 countries, made its first profit in 2004, after reporting a loss of �255m in 2003.