Does the nikon sc-28 ttl cord work with other brand flashguns?

I have a nikon d3100 and I'm about to buy the sigma 610 dg st flashgun. I want to buy the nikon sc-28 ttl flash cord to extend my flashgun. Is sigma flashguns compatible with this cord?

If you get the Sigma model made for Nikon, yes it is. The TTL cord just extends the same contacts as the hot shoe, so any Nikon compatible flash will work off the cord.

It should be compatible if the Sigma flash you get has a Nikon foot*.