WASHINGTON (REUTERS) - Jobs growth in the US since the 2008 recession has been undermined by lower wages, with workers earning an average 23 per cent less than earnings from jobs which were lost, a report by an organisation representing US cities said on Monday.

The average annual salary in sectors where jobs were lost - particularly manufacturing and construction - during the 2008-9 financial crisis was US$61,637 (S$77,031), according to the report by the United States Conference of Mayors (USCM), which represents cities with populations of more than 30,000.

Job gains through the second quarter of 2014 in comparative sectors showed average wages of US$47,171, implying US$93 billion in lower wage income, the report said.

The report also showed that the majority of metro areas - 73 per cent - had households earning salaries of less than US$35,000 a year.

The latest monthly employment data from the Labour Department showed that more than 200,000 jobs were created for the sixth straight month in July, but that wages were about flat in the private sector.

American workers, on average, earned US$24.45 an hour in July, up only a penny from June. Over the last year, wages have grown just 2 per cent, in keeping with where they have been stuck since late 2009.