"We will examine it (the prospectus) rapidly, even before the legal timeframe limit," Giuseppe Vegas was quoted as saying in La Stampa.
Under Italian law Consob has 15 days to look at a takeover offer but can ask for more time if it needs further information. Lactalis filed documents with Consob on Friday.
Lactalis has said it will pay 2.60 euros a share, a total of 3.4 billion euros ($5 billion), to buy the 71 percent of Parmalat it does not already own.
Italy's biggest food group has called an extraordinary board meeting on Tuesday to discuss the Lactalis bid, Il Sole 24 Ore newspaper said on Saturday.
Government sources said last week that a group of Italian companies had dropped plans to make a counter-bid for Parmalat and state holding company Cassa Depositi e Prestiti could safeguard national interests by buying a 10 percent stake.
"It would certainly be difficult to imagine (CDP taking) a stake before the details of the operation are clear," Vegas said in the La Stampa interview.
Asked if he was in favor of lowering Italy's 30 percent ownership threshold for requiring a full bid, Vegas said a lower level could be considered, "providing companies are allowed to introduce defensive rules in their bylaws."
(Reporting by Stephen Jewkes; Editing by Greg Mahlich)