ISTANBUL- Sales of white goods in Turkey tumbled 37 percent in September compared with the same month last year, a sector association said on Thursday, and it called on the government to abolish a special consumption tax to boost the market.

White goods sales shrank 16.3 percent in the first nine months of the year compared with the same period in 2017, reflecting a widespread slowdown in the economy this year, partly driven by a slide in the value of the lira.

"The domestic market contraction continues to gain momentum as a result of financial market volatility. The decline rose to 37 percent in September from 20 percent in August," said White Goods Industrialists' Association chairman Ergun Guler said.

"A temporary suspension of OTV (special consumption tax) is not a solution, indeed it can create problems. OTV must be removed completely in the white goods sector," he told a news conference.

Turkey imposes a 6.7 percent OTV on the white goods sector, Guler said, also calling for the abolition of measures which increase the cost of flat steel, which account for 17 percent of the sector's production costs.

In addition to a regular 9-15 percent customs duty on steel products, a new quota imposed by the trade ministry may push up their cost by a further 25 percent, data from the association suggested.

Lively exports offset a weak domestic market, meaning sales including exports shrank just 1.9 percent year-on-year in the first nine months of 2018 and were expected to contract more than 5 percent for the year as a whole, he said.

Exports rose 4.5 percent in the first nine months of the year to 13.87 million units.

Weak domestic consumption is only now starting to affect the market and it is likely to do so next year, too, when the contraction could amount to 15-20 percent, Guler said.

(Reporting by Ceyda Caglayan; Writing by Daren Butler; Editing by Hugh Lawson) ((daren.butler@tr.com; +90-212-350 7053; Reuters Messaging: daren.butler.thomsonreuters.com@reuters.net))