Pinterest is to expand its ecommerce operations with a $100m investment led by Japanese online marketplace Rakuten.

Alongside existing investors Andreessen Horowitz, Bessemer Venture Partners and FirstMark Capital, as well as a number of angel investors, Rakuten said it aims to continue improving the service as well as expand the community globally.

The partnership also intends to help Pinterest expand into Japan and Rakuten’s other global markets across Asia, Western Europe, and the Americas.

No financial details of the deal were disclosed.

Hiroshi Mikitani, CEO of Rakuten said: “While some may see e-commerce as a straightforward vending machine-like experience, we believe it is a living process where both retailers and consumers can communicate, discover, and curate to make the experience more entertaining.

“We see tremendous synergies between Pinterest's vision and Rakuten's model for e-commerce. Rakuten looks forward to introducing Pinterest to the Japanese market as well as other markets around the world.”

Ben Silbermann, co-founder and CEO of Pinterest, said: “Our goal is to help people discover things they love, by connecting people through their shared interests. Bringing Rakuten on board gives us an amazing opportunity to move a step closer to this goal.”

According to recent stats from Tamba, Pinterest doubled its number of daily unique visitors to 4 million from March to January 2012.