The survey of U.S. adults interviewed for Gallup's Daily Tracking poll found 59 percent of business owners not approving of Obama, a sentiment shared by 57 percent of farmers, fishing or forestry workers interviewed.
Fifty-two percent of professional workers approved of the president compared to 43 percent who disapproved. Among clerical workers 51 percent approved and 45 percent disapproved. Half of service workers approved of Obama while 40 percent disapproved, the poll found.
The survey, which divided respondents into 11 job categories, indicated 47 percent of all workers both approved and disapproved of the president in the second quarter of 2012, a slight improvement from the 45 percent approval and 48 percent disapproval in the first quarter of the year.
Gallup said presumptive Republican presidential nominee Mitt Romney does best among business owners and workers in the farming, fishing and construction industries.
The April 1-June 30 survey of 25,484 U.S. adults at least 18 years of age had a sampling error of 1 percentage point for adults and margin or error ranging from 2 to 6 percentage points for each occupational group, Gallup said.