INVESTORS in open-cast coal miner ATH Resources have been warned their shares may be worthless and around 300 employees in Scotland face an uncertain future after the company was put up for sale.

Meanwhile, workers at Scottish Coal, owned by Scottish Resources Group, have been asked to take a 10% pay cut and prepare for job losses.

Loss-making ATH, which has mines in Ayrshire, Fife and Dumfries & Galloway, has been struggling with a fall in global coal prices accompanied by a rise in its fuel costs.

Less than two weeks after telling investors it was reviewing the business and canvassing support for a refinancing, ATH, which is headed by chief executive Alistair Black, said it had appointed accountant Deloitte to advise on a restructuring and sale.

ATH, Scotland's second-largest coal miner, told shareholders: "Consultations with key stakeholders, including the company's lenders, are continuing, but developments over the past week have led the directors to believe the company is unlikely to attract the level of capital required to continue operating without a restructuring of the group.

"Given the level of liabilities within the company, it is unlikely that shareholder value will be maintained following any possible restructuring.

"Accordingly, the company has instructed Deloitte to advise on all restructuring options that may be available and to assist the board in considering the merit of any proposals from parties who may be interested in investing in or acquiring the business."

Any buyer would have to be able to refinance ATH's £18 million debt load.

Sandra Osborne, MP for Ayr, Carrick & Cumnock, told The Herald said she is seeking a meeting with ATH managers due to concerns about what are relatively highly-paid jobs for the area.

The news prompted another plunge in ATH Resources' shares which tumbled 1.5p or 52.2% to 1.375p. This values the company at just £550,000.

It is potentially another expensive blow for Swedish activist investor Peter Gyllenhammar who recently built a 20% stake in ATH. It comes just weeks after his Leeds Group vehicle took a writedown on its stake in Scottish cashmere company Dawson International.

A spokesman for trade union Unite said its representatives will meet managers of Scottish Coal, the country's largest coal producer, on Thursday to discuss a request that workers take a 10% pay cut or see between 100 and 200 jobs axed.

"We are not going to be prepared to take that 10% cut because there are no guarantees at all it is going to preserve anything," the spokesman said.

Scottish Coal employs around 1000 people.

A spokesman for SRG said: "Due to the low selling price of coal and rising costs, Scottish Coal has been engaged in a process of consultation with its union representatives and employees, about actions that will help to secure the future of the company.

"A consultation process, which is still under way, is based on a package of cost-saving measures which may result in a net loss of between 20 and 100 jobs across all of the company's Scottish operations."

Scottish Resources Group had been close to floating on the stock market in 2010 but scrapped these plans at the eleventh hour. It warned that production in its last financial year to the end of March had been adversely affected by wet weather.