Shares in US retail giant Sears fell 27% by the end of the day in Wall Street after announcing plans to close up to 120 Sears and Kmart stores.Sears Holdings, the department store group which owns the two major retail chains, blamed falling sales.In the eight weeks to Christmas Day, sales at Kmart fell 4.4% and by 6% at Sears.The company, which has 2,200 outlets in the US, says the closures should raise up to $170m (£108.5m; 130m euros).It added that it expected fourth-quarter earnings to be less than half of last year's amount.Retail analyst Howard Davidowitz told the BBC that the news came as no surprise: "Sears took their cash flow and used it to buy back shares instead of enhancing their offer to the customer. This has proven to be a disastrous investment that was made even though the company has been losing market share every single quarter for the past four years."Both Sears and Kmart have experienced a decline in demand for consumer electronics, amid fears of another US recession.Kmart has also reported a decline in clothing sales over the same period.Chief executive Lou D'Ambrosio said: "Given our performance and the difficult economic environment, especially for big-ticket items, we intend to implement a series of actions to reduce on-going expenses, adjust our asset base, and accelerate the transformation of our business model."The results point to "deepening problems at this struggling chain and renewed worries about Sears survivability," said Gary Balter, an analyst at Credit Suisse."The extent of the weakness may be larger than expected, but the reasons behind it are not. It begins, and some would argue ends, with Sears' reluctance to invest in stores and service."The firm's third quarter sales saw the company post a loss due to weakness in its Canadian stores, soft electronics sales and struggles in clothing and pharmaceutical sales at its Kmart unit.