Apple today unveiled a smaller 7.9-inch iPad to accompany its standard 10-inch model. The company made the announcement during a media event in San Francisco that was streamed live on the company's website. 

The new iPad mini will start at $329 for a 16 GB Wi-Fi-only model, putting it in direct competition with companies like Amazon, Barnes & Noble and Samsung, all of which offer 7-inch, lower-priced media tablets. 

Preorders for the Wi-Fi-only models will begin on Oct. 26. Those devices will ship Nov. 2. The company said it will make LTE-capable models available at a later date.  

Apple also unveiled the fourth-generation iPad, which includes an A6 processor, which the company's Chief Technology Officer Phil Schiller said doubles the speed of the third generation iPad. 

Apple's 10-inch iPad has created a market segment all its own. CEO Tim Cook said the company sold its 100 millionth iPad 2 weeks ago. It's those kinds of numbers that have secured Apple's stranglehold over the media tablet market. Still, the smaller, less-expensive version announced today was seen by many as must if Apple is to continue to grow its base. 

Amazon's Kindle Fire, Samsung Galaxy tablets, among others have managed to cut deep into Apple's market share. Apple's 80 percent share dropped to 60 percent over the past year.  

Investors wary of possible cannibalization of standard iPad sales, as well as a price point that might  have overshot its intended competition, sent shares of Apple lower in afternoon trading. Apple was down almost 2 percent to $13.20 following Tuesday's announcement.