BRUSSELS, April 30 (Reuters) - Meta Platforms' ( META )

Facebook and Instagram have failed to tackle deceptive

advertising and disinformation ahead of key European Parliament

elections, the European Commission said on Tuesday as it opened

an investigation into suspected breaches of EU online content

rules.

The move by EU tech regulators came amid concerns about

Russia, China and Iran as potential sources of disinformation,

but also inside the EU, with some political parties and

organisations seeking to attract voters with lies in the June

6-9 vote to select the next five-year parliament.

The Digital Services Act which kicked in last year requires

Big Tech to do more to counter illegal and harmful content on

their platforms.

"We suspect that Meta's moderation is insufficient, that it

lacks transparency of advertisements and content moderation

procedures," EU digital chief Margrethe Vestager said in a

statement.

"So today, we have opened proceedings against Meta to assess

their compliance with the Digital Services Act," she said.

The Commission said it suspects that Meta does not comply

with DSA obligations related to addressing the dissemination of

deceptive advertisements, disinformation campaigns and

coordinated inauthentic behaviour in the EU.

It also singled out the non-availability of an effective

third-party realtime civic discourse and election-monitoring

tool ahead of the elections to the European Parliament.

The Commission also cited concerns about Meta's deprecation

of its disinformation tracking CrowdTangle without an adequate

replacement.

Meta has five working days to inform the EU about remedial

actions taken to address the concerns. DSA breaches can cost

companies fines of as much 6% of their global annual turnover.