Dry bulk shipper DryShips Inc. raised "substantial doubt" about its ability to stay in business after it defaulted on three bank facilities, hit by a prolonged downturn in commodity prices and low charter rates, Reuters reported yesterday. The company's shares fell as much as 26 percent to $1.75 in extended trading on Monday. DryShips, which had total liabilities of $280 million as of March 31, said that it was in breach of financial covenants and has elected to suspend principal repayments and interest payments for the remaining bank facilities. Shippers that transport commodities such as coal, iron ore and grain have been hurt by tepid demand, especially in China, and a surplus of vessels for hire. The company had reported a near 98 percent fall in revenue for the quarter ended March 31 as time charter equivalent, the average daily revenue performance of a vessel on a per voyage basis fell more than 99 percent.