UPDATE 1-Wartsila to cut 1/3 of jobs at ship engine unit

* To cut 400-450 jobs, saving 30 mln eur/year

* Says shipbuilding market has collapsed

(Adds details, quote)

HELSINKI, May 14 (Reuters) - Finnish engineer Wartsila Oyj (WRT1V.HE) said on Thursday it would trim the 1,300-strong workforce at its key ship engine unit by up to one third due to a sharp fall in demand, but stuck to its 2009 forecasts.

"Due to the global economic crisis, the shipping industry and shipbuilding markets have collapsed after a long period of high demand," the company said.

Wartsila said it would cut 400-450 jobs at the unit, aiming to cut annual costs by 30 million euros ($40.9 million).

The impact of the savings will start to materialize gradually from the second part of 2009, and will take full effect by the end of 2010, the company said.

($1=.7327 Euro)

(Reporting by Tarmo Virki; editing by John Stonestreet)