The number of subscribers of mobile virtual network operators (MVNOs) has hit the 7 million mark, the ICT ministry said Tuesday, maintaining stable growth since the service was launched in 2011.

The mobile service providers that rent networks from the country's three carriers -- SK Telecom Co., KT Corp. and LG Uplus Corp. -- had over 7.01 million users as of the end of March, the Ministry of Science, ICT and Future Planning said.

MVNOs usually provide users with plans cheaper than those of the major carriers as they save on network operation costs. In line with its efforts to ease the burden on households amid the economic slump, the South Korean government has been promoting sales of budget smartphones sold by MVNOs.

Since being first launched here in July 2011, MVNO subscriptions surpassed the 1 million mark in October 2012 and continued to gain ground reaching 6 million in January 2016.

"The number of thrift phone users increased on the back of the government's support policy and the operators' rigorous efforts," an ICT ministry official said.

The ministry said the rise in the portion of MVNO subscribers is significant as the average revenue per user (ARPU) of such service providers stands at 16,026 won ($13.6). This is far lower than the ARPU of 36,481 won held by the existing three mobile carriers. (Yonhap)