More apartments are being built in Melbourne than at any time in the city's history, which experts say is being driven largely by overseas investment.

It has also sparked fears of a glut of new apartments, causing property prices to drop once they come to be re-sold.

Almost 6000 homes have been completed or are set to be finished by the end of this year, nearly three times the annual average over the past decade, City of Melbourne development activity data shows.

And almost 6000 more under construction in the Melbourne council area, which covers areas including the CBD, Docklands, Southbank and Carlton, are set to be finished in 2015.

More than half of the 11,546 homes set to be completed in 2014 and 2015 will be in the CBD.