* Growing concern over threat to elections
* Tech firms must do more to close fake accounts
* Online platforms "falling short" of the task
* Tech industry says deadline looks rushed
* King says "million miles" from censorship (Adds tech association comment, King comment)
By Julia Fioretti
BRUSSELS, April 26 (Reuters) - Tech giants such as Facebook and Google must step up efforts to tackle the spread of fake news online in the next few months or potentially face further EU regulation, as concerns mount over election interference.
The European Commission said on Thursday it would draw up a Code of Practice on Disinformation for the 28-nation EU by July with measures to prevent the spread of fake news such as increasing scrutiny of advertisement placements.
EU policymakers are particularly worried that the spread of fake news could interfere with European elections next year, after Facebook disclosed that Russia tried to influence U.S. voters through the social network in the run-up to the 2016 U.S. election. Moscow denies such claims.
"These (online) platforms have so far failed to act proportionately, falling short of the challenge posed by disinformation and the manipulative use of platforms' infrastructure," the Commission wrote in its strategy for tackling fake news published on Thursday.
"The Commission calls upon platforms to decisively step up their efforts to tackle online disinformation."
Advertisers and online platforms should produce "measurable effects" on the code of practice by October, failing which the Commission could propose further actions, including regulation "targeted at a few platforms."
Companies will have to work harder to close fake accounts, take steps to reduce revenues for purveyors of disinformation and limit targeting options for political adverts.
The Commission, the EU's executive, will also support the creation of an independent European network of fact-checkers and launch an online platform on disinformation.
Tech industry association CCIA said the October deadline for progress appeared rushed.
"The tech industry takes the spread of disinformation online very seriously...when drafting the Code of Practice, it is important to recognise that there is no one-size-fits-all solution to address this issue given the diversity of affected services," said Maud Sacquet, CCIA Europe Senior Policy Manager.
The revelations that political consultancy Cambridge Analytica - which worked on U.S. President Donald Trump's campaign - improperly accessed the data of up to 87 million Facebook users has further rocked public trust in social media.
"There are serious doubts about whether platforms are sufficiently protecting their users against unauthorised use of their personal data by third parties, as exemplified by the recent Facebook/Cambridge Analytica revelations," the Commission wrote.
Facebook has stepped up fact-checking in its fight against fake news and is trying to make it uneconomical for people to post such content by lowering its ranking and making it less visible. The world's largest social network is also working on giving its users more context and background about the content they read on the platform.
"The weaponisation of online fake news and disinformation poses a serious security threat to our societies," said Julian King, EU Commissioner for security. "The subversion of trusted channels to peddle pernicious and divisive content requires a clear-eyed response based on increased transparency, traceability and accountability."
Campaign group European Digital Rights warned that the Commission ought not to rush into taking binding measures over fake news which could have an effect on the freedom of speech.
King rejected any suggestion that the proposal would lead to censorship or a crackdown on satire or partisan news.
"It's a million miles away from censorship," King told a news conference. "It's not targeting partisan journalism, freedom of speech, freedom to disagree, freedom to be, in some cases, a bit disagreeable."
Commission Vice-President Andrus Ansip said there had been some debate internally over whether to explicitly mention Russia in the fake news strategy.
"Some people say that we don't want to name just one name. And other people say that 'add some other countries also and then we will put them all on our list', but unfortunately nobody is able to name those others," the former Estonian prime minister said. (Reporting by Julia Fioretti, Editing by William Maclean)