WORKERS at a County Durham factory staged their first strike yesterday over a pay dispute that has rumbled on since July.

Many of the 150 workforce mounted picket lines at the entrances to Hydro Aluminium Extrusions, in Birtley, after rejecting the company's third pay offer on Monday.

Dave Telford, the Amicus union's regional officer, said members were "angry and insulted" by the three pay offers that have been made in the past four months.

"The second pay offer made in September was actually lower than the first, and the third was only slightly higher," said Mr Telford.

"Our members feel that they are entitled to the cost of living and they are not being offered that.

"Hydro is claiming that the Aluminium Extrusion business is struggling at the moment, although there is no fear of redundancies at the moment.

"The majority of the workers have picketed today in the first day of a series of actions. The next strike is scheduled for Tuesday next week."

Sandy Rollo, Hydro's corporate development manager, issued a statement, but refused to comment further on the dispute.

In it he said: "As of today there exists a local disagreement between the management and the Amicus union at our Birtley operation over the current wage negotiations.

"In light of this, we have reviewed a forward order loading and are in the process of putting plans in place to avoid any disruption to our customers. In the meantime it is business as usual for our customers."

Mr Telford said he remains optimistic that the dispute can be resolved in the near future.

"We are waiting for the company to sit down with us round the table and negotiate improvements," he said.

The Birtley site was set up on Durham Road in 1976 as Century Aluminium and was acquired by Norwegian group Norsk Hydro in 1986.

Hydro is the UK's leading supplier of extruded, machined and surface finished aluminium extrusions.

In 1998 the firm invested £11m in an extrusion press, at the time creating 70 jobs. The plant has an annual turnover of £33m.