I'm pretty sure its from Chanel's "Paris New York" (PNY) line. There are several bags that look just like that in this thread from the Chanel Reference Library...
I have it in dark white. It was hard to find, even when it was in season. Occasionally it is on ebay. The new season bags shows a very similar bag, smaller but with the zipper around the bottom.
I have a bag very similar to this. My boyfriend bought it when traveling to Parus. I've been wanting to put it on eBay but wasn't sure the name or details of this bag.