German lighting firm Osram has asked the European commission to consider prolonging EU import tariffs on energy-saving light bulbs from China. The current "anti-dumping" duties are due to expire on 18 October, after the commission and EU governments agreed to extend them by one year at Osram's request last autumn.

On Thursday Osram confirmed it had asked the commission for an "enquiry review" to assess whether the duties should be extended.  The company has also asked for an "interim review" to assess the level of the tariffs, which currently amount to up to 66 per cent of the cost of the imported bulbs.

In a statement the company said it supports free trade and fair competition, and said it had requested the interim review to "make it easier for [Chinese] companies that do not engage in dumping (or only to a small degree) to apply for a reduction in duties".

Last year's extension was opposed by green campaigners, some EU governments and the vast majority of Europe's lighting industry. The decision was seen as a concession to the German government in support of Osram, which at the time was the only major European bulb manufacturer without production capacity in China.

The commission now has until 18 October to decide whether to reject Osram's requests, or to launch a full investigation on either point.  In the latter case, the current duties would remain in place pending the outcome of any investigation.

A spokesman for EU trade commissioner Peter Mandelson said EU rules prevented the commission confirming or denying having received a request from Osram.  "Any requests we do receive will be studied carefully and treated on their merits," he said.

When the one-year extension was agreed last year, Mr Mandelson said a lengthier extension "would have harmed EU consumers more than it would have benefited EU producers".  Last week EU retail association Eurocommerce urged the commission to "take the only responsible decision" and reject any further extension.

Rory Macrae, trade expert at Brussels consultancy GPlus, said a full investigation would likely take up to 18 months and would amount to a "de facto extension of the duties".  "My expectation is that the commission will reject the request, but if not they will be unpicking the deal reached last year and open themselves to accusations of inconsistency".

Osram had issued a legal challenge against last year's decision to only extend the tariffs for one year, arguing that under EU anti-dumping rules any extension must be for a minimum of five years.  But last week the company withdrew its case on the morning that a ruling was due from the European court of justice.

*Meanwhile Mr Mandelson has said the chances of a breakthrough in stalled global trade liberalisation talks in Geneva next week are "improving". One of the issues to be discussed by ministerial representatives at the World trade organisation (WTO) talks is freer trade in environmental goods.  But he warned that a further failure in Geneva "will reduce our ability to pass further tests", such as negotiations on a post-2012 global climate deal.

Follow-up: European commission, tel: +32 2 299 1111, plus Eurocommerce press release . See also Mandelson comments on WTO trade talks