NEW YORK - Sina Corporation's stock price opened 19 percent higher on Monday as it announced that Alibaba Group has invested $586 million to purchase shares of Weibo Corporation, Sina's wholly owned subsidiary, before the opening bell in New York market.

Sina?is a leading online media and Nasdaq listed company, and Weibo is one of its subsidiaries which operates a Twitter-like social media website in China. Alibaba is a leading e-commerce platform.

The shares purchased included preferred and ordinary shares and represented approximately 18 percent of Weibo on a fully-diluted basis.

Sina has also granted an option to Alibaba to enable Alibaba to increase its stake in Weibo to 30 percent on a fully-diluted basis at a mutually agreed valuation within a certain period of time in the future.

Sina also said several of entities affiliated with the company has entered a strategic alliance with several entities affiliated with Alibaba Group, including Taobao (China) Software Co, Ltd and Zhejiang Tmall.com Technology Co, Ltd, to jointly explore social commerce and develop innovative marketing solutions to enable merchants on Alibaba e-commerce platforms to better connect and build relationships with Weibo users.

The two companies would cooperate in the areas of user account connectivity, data exchange, online payment and online marketing, and would explore new business models for social commerce based on the interactions of users on Weibo and on Alibaba's e-commerce platforms.

Sina said the strategic alliance is expected to generate approximately $380 million in advertising and social commerce services revenues in aggregate for Weibo over the next three years.