Executives of Blockbuster have determined what many analysts had concluded from the beginning -- that its offer to buy Circuit City Stores would not be in its best interests. On Tuesday the video rental firm announced that it had withdrawn its offer to buy the home electronics chain "based on market conditions and the completion of our initial due diligence process." However, it maintained, that it continues to believe in the strategic merit of bringing "media content and electronic devices together under one brand." Blockbuster shares rose 12 percent to $2.84 at midday (Wednesday), while Circuit City shares were down 14 percent to $2.19.