TIMBER company Gunns Ltd says it has `substantially progressed its negotiations' with potential joint venture equity partners for the finance of its proposed $2.2 million Bell Bay pulp mill project.In statement to the Australian Stock Exchange this morning the company said a process was being conducted to select a partner to negotiate a joint venture agreement."The company will provide a further market update when the terms of the agreement are finalised, which is expected to be in June, 2009."Most of the environmental and planning approvals for the project are in place with the Federal Government requiring the company to undertake hydrodynamic modelling before the mill can start operating.Gunns announced in February it was calling tenders for the modelling. Construction of the mill will take several years.Anti-pulp mill campaigners moved their protest activity to Bell Bay at the weekend by unfurling a 60m-long banner at the site.