HARGREAVES Services, the company aiming to mop up parts of Scottish Coal, has been granted an extension by the liquidator after missing its due diligence deadline, the Sunday Herald has learned.

KPMG has agreed the Durham-based company can have a week-to-week extension as it decides which of the remaining parts of Scotland's biggest coal-mining producer it wants to buy. Hargreaves was selected as preferred bidder for the assets in May, ahead of two other candidates, after Scottish Coal collapsed in April.

It is understood Hargreaves has confirmed it wants to buy the open-cast mines at House of Water in East Ayrshire and Broken Cross in South Lanarkshire – by far the two most productive of Scottish Coal's six working mines. It is also said to have selected the site at St Ninians in Fife, which has permission for a new mine.

Hargreaves's final decision on the assets has important implications for the 660 miners and support staff who lost their jobs with the liquidation, together with about 70 workers who are still helping with the wind-down, since it will determine how many will be re-employed.

It is also being watched closely by environmentalists, who are anxious to know what will happen to the 11 former mines that were left derelict with the collapse. Mining companies are supposed to set aside cash and keep insurance policies to pay for the restoration of mine sites, but Scottish Coal is short by an amount that looks likely to exceed £100 million. KPMG has petitioned the Court of Session for permission to abandon the sites, but is being challenged by several councils and Scottish agencies. The case is due to be heard next month.

Elaine Murray, Labour MSP for Dumfriesshire, said that the delay to the process was "disappointing". She said: "This should not be allowed to go on for too long. Hargreaves are a major UK company and should be able to put in a reliable bid.

"There were other bidders who appeared to have the backing of fairly major foreign investors, so it is not as if Hargreaves is the only option."

Hargreaves already bought Aardvark (TMC), another company with several mines in Scotland that had gone into administration last year, saving 237 out of around 300 jobs and paying £10.4m.

The company confirmed that KPMG had granted it an extension, but declined to comment on speculation about its preferred sites.