The Skelmersdale based fabricator and erector is now in the hands of administrator Leonard Curtis.
The BCSA member company has been in business since 1978 and employed 55 staff with a turnover of £9m last year.
The company blamed its demise on late payments and dire trading conditions in the steelwork sector.
One source told the Enquirer: “The company has been hit by a reduction in structural steel volumes, the erosion of contract margins, reduced credit with suppliers and extended payment terms across the construction industry.”
The AA Group was a supply chain partner for some of the country’s leading contractors.