Albemarle & Bond is slashing costs and has closed 33 pop-up gold buying stores while it completes the deeply-discounted rights issue.
It said the move would repair its balance sheet.
The group, which had around 230 stores, has also appointed a new chief executive and is in talks with EZCORP, its biggest shareholder, on underwriting the cash call.
It has secured a month's breathing space with its lenders on covenant tests on its £51 million debt pile.
The price of gold has plunged by about a third over the past two years, squeezing the group's profitability and leaving it at "high risk" of breaching banking covenants.
Albemarle said the pop-up stores, which bought jewellery for cash, were no longer profitable.
It said: "The ongoing weakness in the gold price creates significant uncertainty over the company's prospects for the current financial year to 30 June 2014 and for the company's profitability."
Albemarle's lenders have agreed to defer its earnings covenant test until October 30 and the pawnbroker said it is trying to agree a new banking package. Albemarle said a rights issue would be priced at 50p a share and warned there was no certainty the cash call will go ahead.
Shares closed down 50.5p, or 40%, at 74.5p.