(Reuters) – Weibo Corp , the company behind Chinas biggest microblog by users, reported second-quarter revenue that more than doubled, helped by a jump in advertising and marketing sales. Net loss attributable to shareholders narrowed to $15.4 million, or 8 cents per share, in the three months ended June 30, from $35.1 million, or 24 cents per share, a year earlier. Revenue jumped to $77.3 million from $37.6 million. Advertising and marketing revenue increased 99 percent to $59.6 million. (Reporting by Abhirup Roy in Bangalore; Editing by Feroze Jamal)