I did not know about this competition until I found out that a friend of mine had been making progress in this annual competition. It is organised by Mahogany Models and you can follow the competition and read about past winners here.
The final heats are taking place now. So you should go and see one if you can. The prizes include , a modelling contract, the Face of Mahogony 2009, cover shoots, clothes, money and more.
In effect Mahogany Models is
Europe’s largest modelling agency for models of colour. By models of colour we mean models that are of African, Caribbean, Asian, Hispanic, Oriental, bi & multi racial ethnicity.(source)
Youtube channel Naija sounds TV has video links for past competitions.
I cannot really say how it compares to other modelling competitions except it does address a need and a want. I hope this company and competition grows yearly.