By Philip Blenkinsop

BRUSSELS, Jan 23 (Reuters) - Chinese electric vehicle $(EV)$ makers BYD 002594.SZ, Geely 0175.HK and SAIC 600104.SS have challenged the EU's import tariffs at the Court of Justice of the European Union (CJEU), filings on the court's website showed on Thursday.

The European Union imposed tariffs on China-made EVs at the end of October after an anti-subsidy investigation, including 17.0% for BYD, 18.8% for Geely and 35.3% for SAIC, on top of the EU's standard car import duty of 10%.

Court filings show all three have lodged their complaints at the General Court, the lower of two CJEU chambers, on Tuesday, a day before the deadline for filing challenges. Proceedings at the General Court last on average 18 months and can be appealed.

No further details of the cases were given.

The European Commission said it was aware of the cases and had two months and 10 days to prepare its defence.

It is not clear if there have been also challenges from other EV makers, including European firms producing in China, or the China Chamber of Commerce for Import and Export of Machinery and Electronic Products (CCCME), which has represented Chinese EV producers.

The challenges are likely to include arguments over the assessment of subsidies, the establishment of injury to EU industry and the Commission's unusual decision to launch a case on its own, rather than following an industry complaint.

SAIC is expected to take issue with its far higher tariff. This followed a determination that it did not cooperate with the investigation, allowing the Commission to fill in missing sections with selected available facts.

China-based EV makers have also complained that Tesla TSLA.O, the largest exporter of EVs from China into the EU, was not included in the official sample, from which the rate for other companies is calculated. The sampled companies were BYD, Geely and SAIC.

Tesla secured the lowest extra tariff of 7.8%. If it had been part of the sample, cooperating companies would have benefited from a lower tariff than the 20.7% they now face.

(Reporting by Philip BlenkinsopEditing by Tomasz Janowski)

((philip.blenkinsop@thomsonreuters.com; +32 2 585 2869: @reutersPhilB;))