BRUSSELS, July 2 (Reuters) - Europe"s tech chief Margrethe Vestager on Friday warned iPhone maker Apple (AAPL.O) against using privacy and security concerns to fend off competition on its App Store, reasons CEO Tim Cook gave for not allowing users to install software from outside the Store. Vestager, who is also the European Commission"s executive vice president, last year proposed rules called the Digital Markets Act (DMA) that would force Apple to open up its lucrative App Store so that users can download apps from the internet or third-party app stores in a practice known as side-loading. Cook, speaking at an event last month, said the proposal would destroy the security and privacy of iPhones. read more Vestager said she shares Cook"s security concerns. "I think privacy and security is of paramount importance to everyone," Vestager told Reuters in an interview. "The important thing here is, of course, that it"s not a shield against competition, because I think customers will not give up neither security nor privacy if they use another app store or if they sideload," she said. Vestager indicated that she was open to changes in her proposal, which needs input from EU countries and EU lawmakers before it can become law. "I think that it is possible to find solutions to this," she said. Vestager also said Apple"s privacy changes, unlike Google"s plan to block a popular web tracking tool called "cookies" which formed part of her investigation into the Alphabet unit"s digital advertising business opened last month, were not in her crosshairs for now. Apple rolled out an update of its iOS operating system in April with new privacy controls designed to limit digital advertisers from tracking iPhone users. "As I have said, I think actually several times, that it is a good thing when providers give us the service that we can easily set our preferences if we want to be tracked outside the use of an app or not as long as it"s the same condition for everyone. So far, we have no reason to believe that this is not the case for Apple," she said. Apple did not immediately respond to an emailed request for comment.