Figures revealed to the Enquirer show that the CITB employed 1,394 staff last year – more than leading construction names like Lend Lease UK, Seddon, Osborne and Robertson.
Staff numbers have been creeping-up at the CITB since 2010 when they fell to 1,389 after hitting a high of of 1,550 in 2009.
The organisation pays around a third of its levy income in wages.
In 2012 the CITB collected £143m in net levy income from construction companies and its wages bill for permanent staff was £43m.
One contractor said: “The whole of construction has been in a pretty bad place during that time so I don’t see how you can justify increasing staff numbers at the training body.
“It seems to employ a ridiculous number of staff when you consider what we get out of it.”
The CITB employs 76 people in its “Communications & Change” department with 440 working in “Corporate Services.”
The National Construction College employs 274 staff with a further 57 working on “Skills Strategy”.
The CITB will get a new permanent CEO next month when Adrian Belton takes on the £142,000-a-year-role.
Belton is currently the Chief Executive and Accounting Officer for the Food and Environment Research Agency (Fera).
A CITB spokesperson said: “The CITB employs just shy of 1,400 staff who operate across England, Scotland, Wales and Northern Ireland to support over 73,000 construction companies that are within scope of CITB support.
“By any definition, this is a small number of people supporting an extremely large number of companies.
“These are dedicated staff who provide apprentices and administrative support relating to apprenticeship training and development, advice and up-skilling support to existing staff.
“This is also in addition to the work that we do with government and local authorities around procurement KPIs and ensuring local contractors can qualify for public projects – and in addition to support we give to employers to claim grants for training.”