I do beleive there is an adaptor for this type of connection. However, I was never able to find one. I was looking for one a long time ago. I ended up splicing the wire and making a homemade adapter, and eventually replacing the fan. I would try and online vendor, eBay, Radioshack, or a computer show if there is one coming near you soon.
Go to
Pricewatch and search for Cables Fan Adapter. There are several of these types of connectors for under $5.