Troubled listed property trust GPT may have to pay Melbourne's retailing dynasty, the Besen family, up to $600m.

This is the result of a put option that gives the family the right to offload its half-share in one of Australia's best shopping centres, Melbourne's Highpoint, to the trust.

The family, which is headed by Marc Besen and had a $1.75bn fortune according to last year's BRW Rich 200 List, has until March 30 to exercise the option.

If the put is made, it would push Australia's oldest listed property trust close to breaching its debt covenants yet again, after it narrowly averted a breach last year with a $1.6bn capital raising.

The Australian