LinkedIn Corp attracted 6.7 per cent more users last month, when it became the first major US social-networking site to hold an initial public offering, according to ComScore Inc. LinkedIn\'s US user base climbed to 33.4 million in May, following a 2.5 per cent decline in April from March, according to Reston, Virginia-based ComScore. It\'s closing in on the second-biggest US social-networking site, Myspace, which has 34.9 million users. Facebook Inc remains dominant in the field. LinkedIn\'s May 18 IPO raised its profile with investors and helped build publicity around the Mountain View, California-based company. Its shares more than doubled on their first day of trading, though they\'ve since given up some of those gains. To keep expanding its user base, LinkedIn is adding features and letting outside software developers take advantage of the site\'s social graph the map of how everyone is connected. \"Current user growth exhibits strong momentum,\" Ken Sena, an analyst with Evercore Partners Inc. in New York, said in a note initiating coverage on LinkedIn. \"User growth on the platform will remain strong, and we see enormous opportunity to leverage LinkedIn\'s user profile information and social graph for the benefit of third parties building on its platform.\" LinkedIn\'s shares rose $2.44, or 3.4 per cent, to $75.2 on the New York Stock Exchange on Monday. They have climbed 67 per cent since the IPO. The company could increase its global registered user base to more than 500 million by 2017, from 90 million last year, said Sena, who has a neutral rating on the shares. LinkedIn\'s revenue more than doubled to $93.9 million during the first quarter, while net income rose 14 per cent to $2.08 million. Facebook remained the No 1 US social-networking site, with 157.2 million users in May, ComScore said. That was up from 154.1 million in April. Those figures run counter to another report, which found a decline in May. Inside Facebook Gold, which provides data on the social network, estimates that US users fell almost 4 per cent to 149.4 million in the month. From / Gulf News