An eight-year growth spurt for the U.S. aerospace industry appears set to end in 2012, the industry's chief trade group said Wednesday.

Sales are expected to have risen 3.6 percent this year to $218.1 billion from $210.6 billion in 2010, marking the eighth straight year of growth despite sluggish markets worldwide, the Aerospace Industries Association said.

But sales are projected to ebb 0.2 percent to $217.7 billion in 2012, it added in an annual year-end review and forecast.

The outlook for growth is positive in commercial aerospace and neutral in the defense sector, said the group, whose members include Lockheed Martin Corp , Boeing Co , Northrop Grumman Corp and Raytheon Co .

Both the commercial and military sectors remain vulnerable to numerous variables that are capable of overturning current expectations and trends, it said.

Among these are planned U.S. military spending cuts as part of federal deficit reduction efforts.

However, rising commercial aircraft sales (up 7.5 percent year over year through September 2011) could offset these drags on the market and may spur the commercial aviation sector to increase capital spending on new equipment, the association said.

Aerospace exports are expected to have risen to nearly $90 billion in 2011, up 12 percent after having fallen for two years, the report said.

(Reporting by Jim Wolf ; editing by Maureen Bavdek)