CBS has completed its $1.8 billion acquisition of CNET Networks, and has merged the company into a new and expanded CBS Interactive business unit, according to Radio Ink (via MediaBuyerPlanner). comScore ranks the new unit the eighth-largest web network worldwide.

The unit is headed by Quincy Smith, who has been president since 2006 and who will now get to be CEO of the division. CNET CEO Neil Ashe will take over the role of president.

Portfolio points out CNET employees half-expect Smith to repeat his infamous Christmas Massacre of 2007, when he laid off nearly half of the CBSNews.com team.

The expanded unit will encompass five content categories, including technology (led by CNET.com), entertainment, sports, news and business.