Wages in Erie County grew faster than the national average during the second quarter of last year, but even then, they only managed to keep pace with the rising cost of living, a new government report said Wednesday.

Average weekly wages in Erie County grew by 1.7 percent, or $13 a week, to $793 from the second quarter of 2011 through the second quarter of 2012, according to data from the U.S. Bureau of Labor Statistics.

The rise in wages matched the 1.7 percent increase in consumer prices during the same period, meaning that the purchasing power of those higher wages in Erie County essentially remained the same. Weekly wages in Erie County are 12 percent below the national average of $903 and lower than the average in 65 percent of the counties included in the report.

The wage growth put Erie County just outside the top third of all counties nationwide for wage growth, ranking 111th out of the 328 largest U.S. counties included in the report. Among the 18 largest counties in New York, Erie County was one of only four that had wage growth that topped the national average of 1.3 percent, said Martin C. Kohli, the bureau’s chief regional economist.

The report also showed a wide disparity in wages across Western New York, with average weekly wages falling in Niagara, Chautauqua and Allegany counties, while increasing in Wyoming, Orleans, Genesee and Cattaraugus counties.

The report also showed that employment growth in Erie County averaged 0.6 percent during the 12 months that ended in June 2012, just a third of the 1.8 percent increase nationally.

“We’ve got increases in employment and increases in wages,” said John Slenker, the state Labor Department’s regional economist in Buffalo. “That’s good.”

Employment growth in Niagara County was much faster, rising by 1.9 percent, slightly higher than the national average. The average weekly wage in Niagara County slipped $1, to $701 a week, although that could reflect the bump in hiring, since new hires typically start at the low end of the wage scale.

The employment figures in Wednesday’s report are based on more detailed data from the U.S. Census Bureau, which will be used as the benchmark for revised job numbers to be released next week by the New York State Labor Department.

Local economists have raised questions about the accuracy of the preliminary job figures that have been released for much of 2012, which reflect a big drop in employment in the job category that includes temporary help. The economists have said the decline included in the reported numbers is too severe, and they have predicted that the revisions will show that job growth last year was stronger than the 0.2 percent increase that was reported last month.

The strongest growth in average weekly wages came in Wyoming County, with a 2.4 percent increase to $724. In Orleans County, average weekly wages grew by 1.8 percent, to $748, while they rose by 1.3 percent, to $713, in Cattaraugus County. Average weekly wages inched up by 0.2 percent, to $661, in Genesee County.

On the down side, average weekly wages slipped by 0.2 percent in Allegany County, to $662, and by 0.5 percent, to $660, in Chautauqua County.