OSLO, Dec 8 (Reuters) - Growth in the Norwegian business sector slowed considerably over the past three months while the outlook for the next half year remains subdued, a central bank business survey showed on Tuesday.

"Contacts expect lower activity in the period ahead, but a gradual improvement towards spring," Norges Bank said.

The sentiment index, collected from Oct 26-Nov 13, is one of the last domestic data releases ahead of Norges Bank's Dec. 17 monetary policy meeting. (Reporting by Terje Solsvik, editing by Victoria Klesty)