Internet company AOL said Tuesday it had narrowed its net loss in the second quarter and posted an increase in global advertising revenue for the first time in three years.The quarterly growth in ad revenue was apparently not enough, however, to encourage investors -- AOL shares plunged 13.74 percent to $13.00 in early trading on Wall Street. AOL said it posted a net loss of $11.8 million in the quarter compared with a net loss of $1.05 billion in the same quarter a year ago, when it took a hefty accounting charge. Total revenue fell eight percent in the quarter to $542.2 million. Subscription revenue from AOL\'s steadily shrinking dial-up Internet service dropped 23 percent to $201.3 million but advertising revenue grew five percent to $319 million. It was the first quarter of ad revenue growth since the second quarter of 2008. AOL said display advertising revenue, which includes banners, rich media and video, grew 14 percent in the second quarter to $137.6 million, boosted by the acquisitions of The Huffington Post and TechCrunch. \"AOL\'s return to global advertising growth for the first time since 2008 reflects the hard work of our team and another meaningful step forward in the comeback of the AOL brand,\" said chief executive Tim Armstrong, a former Google executive who was brought in two years ago to turn around the struggling company.\"AOL is singularly focused on becoming the next great media company for the digital age and we have positioned the company\'s best people, technology and assets in front of some of the largest opportunities on the Internet,\" Armstrong said in a statement. AOL bought The Huffington Post news and opinion website in March for $315 million and TechCrunch, a leading Silicon Valley technology blog, in September.AOL, formerly known as America Online, fused with news and entertainment giant Time Warner in 2001 at the height of the dotcom boom in what is seen as one of the most disastrous mergers ever.It was spun off by Time Warner in December 2009 into an independent company.