Robert Wiseman and five other Scottish dairies will face no action over alleged market-rigging after the Office of Fair Trading said yesterday that it has closed its two-year investigation.

Robert Wiseman and five other Scottish dairies will face no action over alleged market-rigging after the Office of Fair Trading said yesterday that it has closed its two-year investigation.

A provisional investigation in 2006 found that the six had engaged in price fixing and market sharing.

The OFT said: "Although the evidence at the time was sufficient for the OFT to make a provisional finding of an infringement, as a result of continuing investigations the OFT no longer considers that it has sufficient evidence to proceed."

The agency said continuing with the investigation would not be an appropriate use of its resources.

The six dairies were alleged to have engaged in price-fixing between 2000 and 2003. In addition to Wiseman, the other dairies said to be involved were Ballantyne, Graham's, Quothquan, Renfrew and Scottish Milk Dairies.

The investigation was separate to an ongoing investigation into collusion between dairy groups and the supermarkets, the OFT said.

Robert Graham, managing director of Graham's, the UK's seventh-biggest milk producer said: "We are delighted that the OFT has closed the case ...

"We made it clear from the outset that allegations of impropriety on our part were entirely without foundation and worked with the OFT throughout the process to ensure the reputation of our family business remained intact."

Robert Wiseman Dairies added that the decision "vindicates the position we have always maintained that this case should be closed".

Shares in Wiseman rose sharply after news of the OFT decision, but later pared gains to close up 4.25p to 338.25p.