An overhaul of Melbourne's historic Queen Victoria Market is expected to be one of the city's greatest economic drivers over the next decade.

The City of Melbourne will pump $250 million into revamping the inner-city site and wants to promote extended market trading hours, to seven days a week and evenings.   Lord Mayor Robert Doyle predicts the facelift, the largest investment in the council’s history, will boost the market’s annual turnover from $91 million to $690 million.

“This is about creating one of the great economic drivers of our city,” he told reporters on Thursday at the launch of a draft master plan.  The project, which will include upgraded facilities as well as new event spaces, open areas and car parks, is earmarked for completion in 10 to 12 years.

About 9000 jobs will be created during the construction phase, with an extra 9000 expected as the market grows.  Market trader Karen Birthisel, owner of Garden Organic, said extended trading hours could better accommodate working families.

“It would be nice to update the facilities and get people coming back into the city for their shopping,” she said.

Nut Trek co-owner Diana Mikvlik said the market definitely needed change, but there would need to be trials and ongoing consultation.

“Too much change too soon will alienate the clientele we have now,” she said.

Queen Victoria Market opened in 1878.