The rupee slumped to a record low on Thursday, but heavy selling of dollars by state-run banks probably on behalf of the Reserve Bank helped the unit crawl off the trough at close. Traders estimated the state banks sold up to $1.5 billion to halt the rupee’s slide after it tumbled to 50.60 per dollar in early trade, according to Reuters data, as the stock market extended a slide into a seventh session in a row. A trader said state banks sold dollars aggressively in late trade, helping the rupee climb briefly to 49.88. However, the outlook for the rupee remained weak, he said. The partially convertible rupee closed below 50.