NEW YORK — For the nation's lumber companies, automakers, home builders and other manufacturers, the final half of 2008 may be as sluggish as the first.

Slow consumer spending and high gas prices have stalled manufacturing, and even some bright spots are expected to dim. Exports, which have propped up the sector, may slide as economies overseas slow. Meanwhile, construction spending is at a seven-year low that has spread from housing to nonresidential projects.

The Institute for Supply Management said Tuesday its reading for the nation's manufacturers fell to 49.9 in August from 50 in July, matching economists' expectations, according to Thomson/IFR. A reading below 50 signals contraction, while a reading above 50 signals growth.

The index has hovered near the 50 "boom-bust" line all year and industry groups say they expect similarly weak growth for the remainder of the year.

The second half of 2008 has started especially slowly for certain sectors. U.S. auto sales hit a 16-year low in July, and food manufacturers continue to struggle with inflation. Hormel Foods last month lowered its fiscal-year outlook and Smithfield Foods, the nation's largest pork producer, swung to a first-quarter loss of $12.6 million, from a profit of $54.6 million last year.

On the positive side, inflation appears to be slowing, although it remains elevated. The inflation reading for August was 77, down from June's 91.5, which was the highest since 1979.