The Food and Drug Administration is considering a ban on online sales of electronic cigarettes, as part of a package of regulations the agency is readying for the increasingly popular devices, people familiar with the matter said.

The FDA, which warned in 2009 that e-cigarettes could pose health risks, has been meeting with e-cigarette makers this week to hear their views on its proposed regulations for the industry. The agency is expected to formally unveil its proposals in October, after several delays.

The "listening sessions" at FDA headquarters in Silver Spring, Md., north of Washington, are part of a series of meetings. At least 20 FDA staffers have attended the gatherings, the people familiar with the matter said, as the agency prepares its proposals for public comment.