Construction, accounting and IT training will be offered to 1,700 people in Torfaen, Blaenau Gwent, Caerphilly and Merthyr Tydfil.
Finance Minister Jane Hutt said the aim was to increase workers' productivity.
The Tories' Shadow Economy Minister William Graham accused Labour of favouring their heartland areas in the run-up to the 2016 assembly election.
The three-year Working Skills for Adults 2 project follows a six-year, £10m first phase which covered the same four counties plus Bridgend and Rhondda Cynon Taff.
Working people in four south Wales counties will be given the chance to boost their skills in a £3.8m project.