Data released by the Central Bank shows that 180,796 wireless users had stopped using the service during the second quarter. By end December 2011, there were 2.66 million wireless access users.
Wireline access which is provided by Sri Lanka Telecom, a state joint venture with Malayasia's UT group, grew 5.6 percent to 696,636 by end June.
The firm has said its wireline use is growing with a push to market ADSL (asymmetric digital subscriber lines) services.
Mobile subscribers grew 6 percent to 19.2 million by the end of the fourth quarter.
Sri Lanka has a population of 20.27 million according to the latest census and growth is coming partly from the use of more than one network by a single customer.
Mobile broadband is also a fast growing area.
Internet and email subscribers grew 77 percent to 1.14 million by end June from a year earlier.