When was Norway named Norway?

The first time Norway is mentioned with a name in historical sources, it was still an undefined area. When the chieftain and explorer Ottar met the king of England in the 9th century, his story of the homeland was written down. He calls it Norðvegr, which is directly translated to "north way", not so far from "Norway". Here, the word has evolved into "Noreg", and I suppose that the Dano-Norwegian "Norge" is the Danish version.