Blog Firm Six Apart to Buy Danga Interactive

In another sign that the online journals known as blogs are maturing from a quirky craze to serious business, two start-ups that helped spread the phenomenon are joining forces to create a more diversified company.

San Francisco-based Six Apart, the host of a widely used blogging service called TypePad, is buying Portland, Ore.-based Danga Interactive Inc., which operates LiveJournal, a youthful blogging community. The financial terms of the cash-and-stock deal were not disclosed.