Group-booking and trip management service Groupize has doubled its investment so far with a raise of $2 million from Thayer Ventures and Golden Seeds.
The latest tranche of capital comes almost a year to the day since it raised $2 million from a group of investors, including its newest backer Thayer and Launchpad Venture Group.
Founded in 2010 (TLabs here and its B2B-facing service here), Groupize helps planners book hotel rooms automatically. It has a request-for-proposal (RFP) system for groups of less than 25 rooms.
The company says it is not seeking any additional investment and will use the money expand its sales operations and product development.
In particular will be plans to accelerate the launch of its Instant Book tools for small groups.
Groupize becomes the latest in an increasingly long line of investments from Thayer including Hipmunk, Liftopia, Traxo, Nor1 and Adara.
Golden Seeds has previously backed Triptrotting (now known as GetWist).
Groupize president and CEO, Charles de Gaspe Beaubien, says:

"The marketplace demand for our solutions is timely, as the industry is now focusing on this important segment, and we want to maintain our aggressive development roadmap to bring true solutions to the industry while continuing to be the leaders in online group travel."
He adds that the company is currently powering "one of the largest hotel chains in the world", but is unable to disclose its name.
Clients in the small chain and independent hotel range include Mohegan Sun and Denihan, as well as an agreement with agency consortium Travel Leaders.