Milan's city council will auction 34 percent of airport manager SEA after the summer, a local official said on Tuesday.

The city's executive body unanimously approved the plan to auction the stake to financial and institutional investors in Italy and abroad, ditching a previous plan to list SEA, which runs Milan's two airports.

The stake should sell for at least EUR600 million (USD$727 million), said Mario Talamona, the official in charge of the city's budget.

Talamona added that the Milan city council would probably approve the sale by the end of July, prepare it during August and put SEA on the block "a little after the holidays".

"No extraordinary deals, like mergers or changes to the capital structure, will be able to go through without the approval of the new stakeholder," Talamona said.

The city of Milan owns 84 percent of SEA, which runs the central Linate Airport and the larger Malpensa hub near the foothills of the Alps.

The town hall had originally considered listing SEA in 2005, but then postponed the plan.

Earlier this year, Venice airport operator SAVE floated on the Milan bourse at the top end of its price range and has since risen about 7 percent.