Best Buy has announced plans to close 50 of its 1,100 big box stores nationwide in 2013 and step up efforts to sell mobile and computing products through smaller, "standalone" locations.

The company said it will save $800 million over the next three years by cutting 400 corporate and support jobs as well as the 50 stores. The announcement did not state whether any decision has been made about which stores will be closed.

Best Buy reported a loss of $1.7 billion, or $4.89 a share for the quarter ending March 3, compared to a profit of $651 million, or $1.62 a share for the same period last year. The company said this performance was impacted by $2.6 billion in restructuring costs and other charges.

"In order to help make technology work for every one of our customers and transform our business as the consumer electronics industry continues to evolve," CEO Brian J. Dunn said Best Buy will be "closing some big box stores" and "adding Best Buy Mobile stand-alone locations."

Dunn said the moves are designed "to provide a better shopping environment for our customers across multiple channels while increasing points of presence, and to improve performance and profitability."

One report, by CDNET, attibutes the changes to increasing pressure from online retailers, especially Amazon.

The Best Buy announcement also said the chain would cut 400 jobs in "corporate and support areas" and achieve additional savings "in cost of goods sold driven by reduction of product transition costs, lower product return and exchange expenses and supply chain efficiencies."

An expansion of customer benefits in Best Buy's "Reward Zone Silver" loyalty program is also planned, including "free expedited shipping, premier access to many of the most popular products and major sales events, a free house call from the Geek Squad, and 60-day no hassle returns and price-match policy."