UPDATE 1-Finnair pilots threaten strike for Nov 16 -union

* 800 pilots may go on strike on Nov 16

* Union riled by Finnair outsourcing plans

* Shares unchanged

(Adds further details)

HELSINKI, Oct 30 (Reuters) - Pilots at Finnish national carrier Finnair (FIA1S.HE) may go on strike on November 16 unless the pilots and their employer come to an agreement, the Finnish Air Line Pilots' Association said on Friday.

Like other airlines, state-controlled Finnair has slashed capacity, cut jobs and launched a number of cost saving programmes as the economic slowdown has reduced demand.

"Our aim is still to find a work agreement," the union chairman, Kristian Rintala, said, adding a strike would concern 800 Finnair pilots.

"But if we do not come to an agreement we will proceed with the strike," he added.

He said the strike would affect Finnair's domestic and international traffic.

The struggling carrier reported a slightly bigger than expected loss in the third-quarter on Thursday, and said sales slumped 22 percent on a year ago as business travel and average ticket prices continued to fall.

Rintala said negotiations -- continuing since November last year when the pilot's latest collective agreement expired -- had come to a head recently as Finnair has started to outsource some routes.

In the event of a strike Finnair will operate as many flights as possible with the help of supervisors or outside workers, it told Finnish news agency STT.

Shares in Finnair were unchanged at 3.85 euros at 1409 GMT. (Reporting by Eva Lamppu; Editing by Greg Mahlich)