Blogging software vendor Six Apart has created an ad network to help bloggers monetize their sites.

The opportunity is exclusive to blogs using software packages on its network, which includes Vox, TypePad and LiveJournal, which was recently sold to a Russian firm. Movable Type bloggers are not included.

The newly minted Six Apart Media will use tools from Adify to manage inventory across the breadth of blogs using its hosted software packages.

As explained on the Everything TypePad blog, publishers may opt in to the network. The company will publish ads on blogs that choose not to participate. Publishers may also reject advertisers they don't like.

Revenue will be split between the publisher and Six Apart. The ad network is currently in invitation-only beta.

Of late, creating proprietary ad networks has become popular among companies building small online empires independent of large portals. Last month ESPN made news when it publicly announced its decision to stop focusing on outside ad networks and prioritize in-house sales.