ONE of south-west Scotland's major employers is to relocate to England with the loss of 160 jobs, while in the north-east 200 jobs are under threat at a long-established industrial tooling factory after the parent company announced yesterday it is carrying out a ''rationalisation'' of its business.

Caradon Stelrad, which makes central heating radiators at Dalbeattie, said the plant closure would be phased over the next nine months unless a viable alternative could be found.

The plant has been operating at Dalbeattie for the past 40 years and has been the mainstay of the local economy. At its peak it employed more than 250 workers and in the early 1990s Caradon spent more than #40m on modernisation and introducing new radiator models. The company said it had been forced to review its UK operations - at Dalbeattie and Mexborough in South Yorkshire - in response to a combination of factors.

It said the market had been static over the past 10 years. Against this background there had been intense price competition which had seen the company's share in the market decline and led to its two sites operating at about one third of potential capacity. To remain competitive the company needed to reduce its cost base significantly.

A company spokesman said it was ''with great sadness'' it had decided to close its Edingham Castle plant at Dalbeattie and concentrate production in South Yorkshire.

Mr Brian McCluskie, plant manager, said: ''We deeply regret any job losses but unfortunately this is unavoidable. It is no reflection on an excellent and flexible workforce. The choice to close Dalbeattie has been forced because restrictions of the site, which is more than 50 years old, cannot offer a cost effective solution for the consolidated venture, while Mexborough can.''

In Peterhead yesterday, Green-field Industries, which has two sites - one in the Aberdeenshire port and one in Sheffield - producing similar work, called a meeting of its 200 employees to announce it was carrying out a ''rationalisation'' of its business.

The company released a statement which made it clear that the Peterhead factory, operating under the Cleveland name, was the more vulnerable.

''As the manufacturing process in Peterhead and Sheffield is very similar, the options include a reduction in size of the two plans or the closure of one of the sites. If closure is an option, it is considered more appropriate at this stage that the Peterhead plant would close with the transfer of manufacturing operations to Sheffield.''

The Sheffield base has greater manufacturing capability and is closer to key customers. ''It ap-pears, therefore, this option would result in the biggest cost savings.''