FORTUNE -- AT&T (t) buying DirecTV isn't the only deal going on in the tech space early this week.
Though it may not be quite as earth-shattering as that telecom merger, YouTube's reported plan to buy Twitch would represent the former's biggest acquisition ever.
The deal would be for $1 billion, according to a report in Variety. Twitch is a videogame streaming service, allowing gamers to upload live feeds of themselves playing games that are watchable from videogame consoles.
YouTube's attorneys are preparing for a potential antitrust challenge to the deal, according to the report.
Twitch was launched in June 2011. It boasts more than 45 million visitors per month, according to its website. YouTube, which revolutionized online video and was launched in 2005, was purchased by Google (goog) in 2006 for $1.65 billion.