The blogging service Tumblr is close to raising $75-$100 million in venture capital, implying a market value of $800 million, the Wall Street Journal reported, citing people familiar with the matter.

Greylock Partners, whose portfolio companies include daily deals company Groupon and bed-for-rent service Airbnb, was named as one of the big firms that is taking part in the deal, according to the report.

Tumblr and Greylock could not be reached immediately for a comment on the report.

In June, mobile location based start-up, Foursquare raised $50 million in a round of financing lead by venture capital firm Andreessen Horowitz.

Tumblr counts Spark Capital, Union Square Ventures, and Sequoia Capital, among its existing investors, according to its website.

(Reporting by Saqib Iqbal Ahmed in Bangalore; editing by Carol Bishopric)