Write one symbol over another

[racoon]

Hi,

I would like to write a minus (-) over a delta (\delta). By over I do 
not mean above but that the minus stroke through the delta. (I need it 
to be the minus and not some other strike through version.)

I played a bit around with \mathrlab, \mathclap, and \mathllap but could 
not figure it our.

I managed to get it done with four negative spaces (\!) but that is 
probably not the correct way to do it.

Any ideas?

Daniel