Lenders including Crédit Agricole, Halcyon, Intesa Sanpaolo, Lloyds, Nordea, SEB, BNP Paribas, and Royal Bank of Scotland reduced the company's debt to €257.1m from €487.7m previously.
The senior lenders reportedly wrote off 40% of their debt while the second lean holders wrote off €43m in claims; they will jointly own an 85% stake in the business.
This effectively wipes out the 85% stake owned by private equity firm 3i which acquired GGP from ABN AMRO Capital and AAC Capital Partners in October 2007.
3i invested €260m in GGP when it bought the company for €730m.
A company statement said the agreement represents the first step for the birth of the new GGP, which can now focus on the future.
It said the deal ensures long term-financial stability and allows it to implement a restructuring process focused on commercial, logistic and productive areas.
GCP CEO Georg Metz said: "This financial restructuring marks a key milestone in the history of GGP, putting the whole Group on a sound financial footing, with a stable and solid capital structure which allows us to concentrate on innovation and satisfaction of our clients only. Furthermore, together with our new owners, which put a huge effort to help in designing and finalizing this transaction, we could pursue growth opportunities and improve our strategic positioning all over the world."
GCP runs subsidiaries in 14 countries and owns four consumer brands - Stiga, Castelgarden, Mountfield, Alpina - five production units - and GGP lawnmowers are sold in more than 80 countries all over the world.