Major trading house Itochu Corp. is investing in Docquity Holdings, a Singapore-based operator of a specialized social media network for doctors, to expand its health care business in Southeast Asia.

By investing $6 million through private share placements, Itochu became a "major" investor in Docquity last month, Itochu spokesman Kenji Katsumoto said Monday.

Docquity does not charge doctors to use its networking service. Instead, it earns fees from pharmaceutical firms and makers of medical equipment in exchange for allowing them to post information about their products and services, Katsumoto said.

It currently connects about 80,000 doctors across Southeast Asia, Itochu said in a statement.

Katsumoto said the number of doctors registered with the networking service initially increased between 3,000 and 5,000 a month.

The service enables doctors to share up-to-date information about treatments and medication with a goal of narrowing the gap in medical expertise among Southeast Asian countries. More than 50,000 doctors are registered for the service in Indonesia, over half of the country's total physicians, while the remaining members practice in Malaysia, the Philippines and Thailand.

There are an estimated 41,000 doctors in Malaysia, 126,000 in the Philippines and 27,000 in Thailand, according to Katsumoto. The spokesman said Itochu aims to expand the number of Docquity doctors via its network of medical institutions in Asia, while also involving Japanese pharmaceutical and medical equipment companies to enhance the content of the platform.

Docquity was founded by Indranil Roychowdhury in India in 2013 and is headquartered in Singapore.