
The shares have been suspended because SMG has not had assurance from its banks regarding future financial support. Its lead lending bank is Royal Bank of Scotland.
The group blamed the weather for its financial position.
A statement said: "The company has experienced an insufficient recovery in trading since the adverse weather in December 2010, with consequential pressure on the company’s working capital position."
SMG has been struggling to manage its debt since its stock market listing in 2007, after its £50m reverse takeover by Interactive World.
David Sullivan, founder of the Daily Sport, returned to help the group in 2009, lending it £1.68m, just two years after selling the tabloid newspapers. He also took on an honorary role at the company.
In 2010, SMG reported a pre-tax profit of £330,000 – its first pre-tax profit in two years.
But last year it highlighted that it was experiencing trading difficulties, saying that it had been forced to defer loan repayments to RBS.