By Dhanya Skariachan (Reuters) - Best Buy Co Inc reported weak quarterly sales on Tuesday and warned that a slew of investments to entice shoppers could squeeze profits in the near term. The news overshadowed its better-than-expected first-quarter profit and sent shares of the world's largest consumer electronics chain down 4 percent in premarket trading. Net earnings from continuing operations fell to $97 million, or 29 cents a share, from $169 million, or 49 cents a share a year earlier. ...