The central bank sold $100 million at a forex auction and traders reckoned it sold a further $150-200 million during a fourth consecutive day of interventions. The bank confirmed intervening in the market without disclosing how much it sold. Since last Friday, the total amount sold by the central bank during the direct interventions and forex auctions has reached nearly $4-4.5 billion. European stocks and the euro fell as the sale of 10-year Bunds, which drew a subdued response, and a deeply discounted rights issue by Italian bank UniCredit stoked concerns about euro zone debt. By 1628 GMT the lira stood at 1.8832 versus the dollar, easing back from 1.8612 during the intervention and compared with 1.8765 late Tuesday. "The central bank's actions remain insufficient to support the lira. I think today's intervention was targeting the lira's value versus the (euro-dollar) basket and succeeded in pushing it to near 2.15. As this is a reasonable level, the central bank stopped intervening," said a forex trader at an Istanbul bank. Against the basket, the lira traded at 2.1588 after hitting 2.1463 during the intervention, from 2.1597 early on Wednesday morning and compared with 2.1595 in late trade on Tuesday. The lira weakened nearly 22 percent versus the dollar in 2011, fuelling inflationary pressures, and on Dec. 28 hit its weakest ever level of 1.9215. Istanbul's main stock index closed down 2.51 percent at 51,532.56 points, underperforming the MSCI emerging markets index which fell 0.36 percent. Shares in Tupras - Turkey's biggest crude oil importer owned by its largest conglomerate Koc Holding - dived 6.52 percent after European Union governments reached a preliminary agreement to ban imports of Iranian crude. The yield on Turkey's benchmark bond maturing on Dec. 4, 2013 closed at 11.43 percent, up from its intraday low but down from its previous close of 11.53 percent. "The selloff of the front end of the yield curve increased after the central bank said additional monetary tightening will continue. We expect the benchmark yield to stand around 12-13 percent under current funding conditions," said Tufan Comert, a strategist at Garanti Securities.