The Norwegian Royal Court has confirmed that in addition to Johan Martin Ferner's widow Princess Astrid Mrs. Ferner, King Harald V, Queen Sonja, Crown Prince Haakon, Crown Princess Mette-Marit, Princess Märtha Louise and Ari Behn will all attend the funeral service, which will take place at Holmenkollen Chapel on Monday 2 February 2015.
The late Johan Martin Ferner's nearest family is of course also expected to attend, in addition to other Ferner relatives. Some of the Lorentzens might fly in from Brazil. Erling Lorentzen, who celebrates his 92nd birthday today, seems to be in good shape for his age, but could still find the long flight too tiresome.
The funeral will be a private affair without media presence. I doubt that there will be many, if any, members of foreign royal families present, as the historian Trond Norén Isaksen has also commented on in his blog article of Monday 26 January 2015.