There are indeed two variations available from Australia at least that do not require RTW travel.

3 Continent Oneworld circle trip AUS-Asia-Africa-AUS

4 Continent Oneworld circle trip AUS-Asia-Europe-Africa-AUS

There are some rule variations from the standard Oneworld RTW fares. eg stopovers are limited to 2 in each continent and the 4 continent fare allows a maximum of only 6 stopovers in total as opposed to a maximium of 19 stops 0n the 4 continent RTW fare or more if you buy extra segments.

For complete rules go to www.travel.com.au and type in SYD-JNB return for the 3 continent and SYD-LHR return for the 4 continent.

Pricing is exactly the same as the RTW Oneworld Explorer fare