The number of subcontract workers in the country surpassed the 100,000 mark last year, government data showed Thursday.

According to the data released by the labor ministry, workers hired by in-house subcontractors totaled 106,601 in 2011, up 7.2 percent from a year earlier.

First adopted during the Asian financial crisis in 1998, an in-house subcontracting system has been widely used by local companies to meet the demand for a trained work force. However, concerns have mounted that the companies are abusing the system to minimize labor costs by avoiding hiring regular workers and only using temporary workers employed by in-house subcontractors.

The total number of subcontract workers was only 41,545 in 1998, however, the growth pace accelerated in the late 2000s to reach the 80,000 mark in 2009, according to the ministry.

The number of subcontract workers has notably soared by 43 percent under the incumbent Lee Myung-bak administration, which is more than double the pace seen under the preceding Roh Moo-hyun administration, when it went up by 17 percent.

The average monthly wage of subcontracted workers in 2011 was 1.54 million won ($1,352), the ministry said. Meanwhile, regular workers were payed 2.39 million won on average in the June-August period of last year, according to Statistics Korea.

Also, the number of in-house subcontractors has increased by 13.7 percent to 1,813 in 2011 and companies that use subcontracted workers also expanded by 13 percent to 102,811 in the same period, the ministry added. (Yonhap News)