A sizable revision may be in store for the unit labor costs reported Tuesday morning, a Bureau of Labor Statistics economist said Tuesday afternoon, though it's significance would be limited in a monthly number expressed as an annual rate. The 2Q unit labor costs number announced Tuesday -- which came in at 2.1% instead of the expected level of 3.4% -- should be viewed with a grain of salt because the number will most likely be revised, according to Mark Harper, a senior BLS economist. In fact, he said, it could be revised down as much as 1.6 points or up by as much as 1.8 points when the relevant surveys are completed. U.S. 2Q Unit Labor Costs rose just 2.1%, in contrast to economists' estimates for a gain north of 3%, and U.S. 2Q nonfarm productivity came in at +2.5%, the Labor Department said Tuesday. The lower than expected ULC number suggests corporate profit margins were helped by quick adjustments made in business. Hours were cut more than output in Q2 as businesses adjusted down for slower growth. ULC last rose so slowly in 2Q:2000, at a 1.2% revised gain.