Traditional owners in Arnhem Land in the Northern Territory will sign a landmark agreement today giving them a stake in a lucrative pearl farming venture near Croker Island.

The four-year agreement is the first of its kind in the Territory covering only the sea.

The company Kailis has farmed pearls in the waters between Croker Island and Coburg Peninsula for a number of years by suspending oyster shells on the seafloor.

The High Court has recognised native title over the seas surrounding Croker Island but only where there is not a competing commercial interest.

Today's agreement will allow Broome Pearls, a Kailis subsidiary, to expand its pearl farming free of native title concerns.

In return it will offer traditional owners a stake in the business, including jobs and financial benefits, as well as a say over the protection of sacred sites.