OTTAWA - Statistics Canada says the underground economy totalled $42.4 billion in 2012, roughly 2.3 per cent of gross domestic product.

The agency says that's down from a high of 2.7 per cent in 1994, but up from 2.2 per cent in 2000.

The residential construction industry accounted for the largest portion of the underground economy at 28.3 per cent.

Finance, insurance, real estate, rental and leasing and holding companies amounted to 13.8 per cent, retail trade totalled 12.2 per cent and accommodation and food services was 11.6 per cent.

Statistics Canada says the total value of underground economic activity in 2012 was the highest in the country's four largest economies.

Ontario totalled $15.3 billion, Quebec was $10.4 billion, British Columbia amounted to $5.9 billion, while Alberta was $4.8 billion.