GPT Group has written down the book value of its assets by $1.4bn, including $700m on its Babcock & Brown joint venture in Europe.

It is also taking a $900m loss on its forward derivative book because of adverse movements in currency and interest rate markets.

The effective $2.3bn write-off is equal to GPT's entire market value, which stood at $2.3bn yesterday -- down from $7.77bn a year ago.

The Australian