Community Trust South announced yesterday it would invest $20 million in the project.
HWCP director Scott O'Donnell said it was a ''great relief'' to finally have all the funding for stage 1, 2 and 3 of the project sorted.
This part of the project, which has an estimated cost of $165 million, comprises the demolition and construction of a precinct which will include retail, car parking and a food court, inspired by the ''Little High'' food court in Christchurch.
The Richardson Group, businessman Geoff Thomson and the Invercargill City Council have agreed to invest up to $25 million each.
The Government's Provincial Growth Fund announced a loan of $19.5 million and now Community Trust South had completed the required funding.
A bank loan would fund the remaining $50 million, Mr O'Donnell said.
''It has been three years of hard work. The funding puzzle now is complete. Now we are ready to build.''
The remaining stages of the development - from 4 to 6 - will have private funding. Those stages include the HWR office tower, a medical centre and possibly an accommodation building for SIT.
Community Trust South deputy chairman Lindsay Wright said the trust was pleased to be able to ensure the project would go ahead.
Mr Wright believed the rejuvenation of the Invercargill inner city was a key part of the Southland Regional Development Strategy to bring 10,000 extra people to the region.
''A revitalised city is fundamental to ensuring we can attract and retain people in the region and will help leverage other development including new office space, accommodation and a medical centre.
''The Community Trust South funding has enabled the development to reach a critical stage in the project, which will ensure the future of our city.''
CTS chairwoman Penny Simmonds, who is also SIT's chief executive, has declared a conflict of interest over the decision on the CBD investment.
She said she had not been involved in the final decision on the investment.
