TOKYO (Reuters) - Japan’s real wages declined in September for the first time in three months as inflation picked up faster than growth in nominal pay, the government said, a sign of global cost-push inflation starting to affect Japanese households. In September Japan’s core consumer price index (CPI) posted 0.1% growth from a year earlier, the first positive figure since March 2020, driven by rising energy and raw material costs. Inflation-adjusted real wages, a key gauge of households’ purchasing power, fell 0.6% in September compared with the same month a year earlier, the labour ministry said on Tuesday. It was the first decline in three months after a downwardly revised 0.1% gain in August, due to accelerating consumer price inflation. The CPI measurement now used by the labour ministry to calculate real wages is different from one closely watched by the Bank of Japan, as the former index still sets its base year to 2015, not 2020, and includes volatile fresh foods but excludes owners’ equivalent rent. This version of CPI posted 0.9% year-on-year growth in September, the fastest pace since December 2019. Nominal total cash earnings rose for the seventh straight month, up 0.2% in September from a year earlier. It followed a downwardly revised 0.6% advance in August. Regular pay, or base salary, which makes up most of total cash earnings, was up 0.3% after an upwardly revised 0.5% rise the previous month, the data showed. Overtime pay, a barometer of strength in corporate activity, grew 4.4% year-on-year in September, gaining for the sixth straight month but slowing from double-digit figures in three months to July. The apparent slowdown came largely from a statistical effect reflecting narrower drops in the months toward the end of 2020, a government official said. Special payments, which mainly consist of volatile one-off bonuses, fell 2.3% in September from a year earlier, according to the data. The following table shows preliminary data for monthly incomes and numbers of workers in September: ---------------------------------------------------------------- Payments (amount) (yr/yr % change) Total cash earnings 270,019 yen($2,382.17) +0.2 -Monthly wage 263,276 yen +0.3 -Regular pay 245,835 yen +0.1 -Overtime pay 17,441 yen +4.4 -Special payments 6,743 yen -2.3 ---------------------------------------------------------------- Number of workers (million) (yr/yr % change) Overall 51.927 mln +1.1 -General employees 35.710 mln +0.8 -Part-time employees 16.217 mln +1.7 ---------------------------------------------------------------- The ministry defines “workers” as 1) those who were employed for more than one month at a company that employed more than five people, or 2) those who were employed on a daily basis or had less than a one-month contract but had worked more than 18 days during the two months before the survey was conducted, at a company that employs more than five people. To view the full tables, see the labour ministry"s website at: here ($1 = 113.3500 yen) Reporting by Kantaro Komiya; Editing by Mark Heinrich