* GM vows to boost GMC truck, crossover output-sources
* Sierra pickup to get a refreshed design, new interior
By Deepa Seetharaman
DETROIT, Oct 6 (Reuters) - General Motors Co expects to boost availability of key trucks and crossovers sharply for the 2011 model year, four people briefed on the plans said on Wednesday.
The outlook, which was presented at a meeting of GMC and Buick dealers convened in Detroit, comes at a time when some analysts have raised concerns about whether industry-wide gains in North American auto production in 2010 would be sustained next year.
GMC and Buick dealers were told by GM executives that the top U.S. automaker would look to boost production and increase availability for the 2011 model-year in key vehicles including the Sierra, Terrain and Acadia, the sources said.
In addition, GM executives said the automaker planned to roll out a revamped version of the Sierra truck with a more luxurious interior, three of the sources said.
The sources asked not to be quoted about the content of the closed-door meeting because GM has not made the plans public.
Production of the GMC Sierra pickup truck and the Acadia crossover could be boosted by about 15 percent for the 2011 model year, two people briefed on the plans said.
In addition, GM plans to increase output -- and the availability of the Terrain -- by a substantial margin, the two other sources said.
GM spokeswoman Dayna Hart declined to comment on the content of the private dealer meeting.