Have a look in the back of Flight International. This week 3-9 Dec there are 8 companies so advertising. However, they are probably all fixed-wing.
I'm not sure if the moderator allows advertising for pilots as such...but give a few details and your e-mail number and I'm sure you will get a useful response.
I do NOT work for Flight but an ad will get you more response than you can deal with if the job looks interesting/ rewarding. If on the other hand its 2 on, 1 off in Nigeria, forget it!