Sharp said Friday that its loss in the nine months to December doubled to $4.6 billion as the embattled Japanese electronics giant struggles to repair its tattered balance sheet. But the company offered a glimmer of hope, as it eked out a small operating profit in the third quarter. For the nine-month period, Sharp said it lost 424.35 billion yen ($4.6 billion), while keeping its full-year net loss estimate unchanged at 450 billion yen. During the same period, its operating loss reached 166.23 billion yen on sales of 1.78 trillion yen, down 6.4 percent. Sharp said that in the three months to December it posted a 2.6 billion yen operating profit, the income it makes from its core business. The maker of Aquos-brand electronics, like rivals Sony and Panasonic, has been hammered by credit rating downgrades and record losses, which saw the century-old firm warn about its own survival last year. In a bid to return to profitability, Sharp is undergoing a painful restructuring including thousands of job cuts and slashed wages for employees -- from the factory floor to the executive boardroom. It also said it would put up real estate as collateral for desperately needed bank loans, including its Osaka headquarters, as it pursued tie-ups with domestic and foreign firms.