A UNION has warned of a potential health and safety "catastrophe" in the North Sea oil industry as energy giants Royal Dutch Shell and Taqa announced plans to cut hundreds of jobs.

Shell is to cut 250 jobs in its North Sea operations and introduce changes to shift patterns. Staff and agency contractors based in Aberdeen and on installations in the North Sea were informed yesterday.

And Abu Dhabi-based Taqa said it planned to cut about 100 jobs because of the "challenging" time facing the industry.

Shell said its plans would affect staff and agency contractors and were part of a range of initiatives to manage costs and improve the competitive performance of its operations around the world.

It said it would switch to an "even time" offshore shift pattern, an industry-wide cost-cutting move that is being steadfastly fought by trade unions.

It is the latest move by energy firms to cut costs as oil prices have plunged by nearly 50 percent since last summer.

Unite, the offshore industry's biggest trade union, is concerned that quick-fire cuts to jobs and pay generally will have a detrimental impact on the future prosperity and safety of the industry in the long term.

A Unite spokesman said: "Our fear is by imposing longer shifts in the offshore environment, while cutting back human resources to the bare bones and more, the offshore industry will seriously compromise workplace health and safety. "

A consultative ballot of Unite's membership in the Offshore Contractors Association is taking place.

Unite's Scottish secretary, Pat Rafferty said: "There is no doubt we are witnessing a concerted effort by the offshore industry to impose a race to the bottom on jobs, terms, conditions and ultimately safety across the North Sea.

"The only barriers to the industry's ongoing attacks are the offshore trades unions but we need our politicians to wake up to the reality of what's happening in the North Sea - it's a growing scandal which could turn into a catastrophe."

He pointed out that last week the industry got a £1.3 billion tax break in the Chancellor's Budget which it was claimed was necessary to boost growth and sustainability.

In his Budget statement, the Chancellor said Petroleum Revenue Tax (PRT) would be cut from 50 per cent to 35 per cent to support continued production in older fields.

The existing supplementary charge for oil companies would also be cut from 30 per cent to 20 per cent, backdated to January.

Mike Tholen, economics director of offshore industry body Oil and Gas UK, said: "While these are tough decisions to take given the impact on people, the measures are being taken by many companies and will allow the UK to benefit in the long-term from a boost to energy security, hundreds of thousands of highly skilled jobs and billions of pounds worth of supply chain exports."

Paul Goodfellow, Shell's upstream vice president for the UK and Ireland, said: "The North Sea has been a challenging operating environment for some time. Reforms to the fiscal regime announced in the Budget are a step in the right direction, but the industry must redouble its efforts to tackle costs and improve profitability if the North Sea is to continue to attract investment.

"Changes are vital if it is to be sustainable. They will be implemented without compromising our commitment to the safety of our people and the integrity of our assets."

The Shell cuts are in addition to 250 job losses announced last August.

Shell employs around 2,400 staff and agency contractors in its North Sea business, but that figure will fall by the end of the year after the two job loss announcements.