New Delhi, March 3 -- Activist investor Elliott Investment Management is investing $1 billion in Pinterest Inc., with the funds set to support the social media company's years-long effort to buy back shares, Pinterest said in a statement.

The announcement led to a surge in the company's shares, as they opened 7.6% higher on Tuesday, reflecting strong investor optimism over Elliott's involvement.

Pinterest, a visual search and discovery platform, is headquartered in San Francisco and has over 600 million monthly active users worldwide, according to the company.

The latest share buybacks will be carried out as part of a new $3.5 billion programme approved by Pinterest's board on Tuesday, according to a company statement. In addition, Pin...