Canwest Global Com­munications shares lost more than half their value Thursday in the heaviest trading of the battered stock in nearly eight years.

The media giant’s shares fell 7.5 cents to close at 6.5 cents on the Toronto Stock Exchange, a drop of nearly 54 per cent, on a volume of nearly 10.2 million shares traded. A company once worth more than $2 billion years ago and about $600 million in early 2008 now has a stock market value of just less than $7 million.

The heavy trading triggered speculation the company could be on the brink of filing for bankruptcy protection. Canwest, which reports its third-quarter earnings Friday, is struggling under about $4 billion in debt.