UK glassmaker Pilkington said recently it would enter the Iranian market by building a new glass plant there, but its shares fell on concern over its U.S. automotive unit. Pilkington Plc, which announced last month its invention of the world's first self-cleaning glass, said the new Iranian plant would have capacity of 180,000 tonnes per year. A company spokeswoman told Reuters the plant should generate about 30 million pounds ($42.92 million) in annual turnover. However, shares fell on a cautious outlook for its U.S. automotive business. The group said production had slowed down in the second half of the year, as lower overall demand led to manufacturers closing plants. Under the Iranian deal, Pilkington will take a minor equity stake in Iran's Ghazvin Glass Co. and will jointly control the business. Ghazvin reported last year earnings of eight million pounds, on turnover of 19 million pounds, according to Pilkington.