New York - Tumblr, the provider of a publishing platform for mixed-media blogs and social networks, announced on Thursday that it has closed a $4.5 million second round of funding, led by Union Square Ventures and Spark Capital.

New York - Tumblr, the developer of an online scrapbooking service, has raised $750,000 in first round finding from Spark Capital and Union Square Ventures, PEHub.com reported, citing a regulatory filing.