California's new health-insurance exchange, the biggest of the state marketplaces emerging under the federal health-care overhaul law, said there was a possibility consumers won't initially be able to enroll in coverage online when it is launched on Oct. 1.

Peter V. Lee, executive director of Covered California, the state agency creating the exchange, said Thursday in a meeting of its board that the agency potentially would "phase in support" for the exchange, starting with allowing offline means of sign-up and later adding the ability to fully enroll online.

Either way, consumers are expected to be able to obtain health plans by speaking with counselors on the phone or in person.

Mr. Lee said the exchange agency is "absolutely confident that we will be live and serving consumers Oct. 1." He pointed to Oregon, where the exchange has said consumers won't be able to access it online in the first few weeks after Oct. 1, and said California's exchange has "not yet made that call at this point." But he wanted to "make sure we're managing expectations" about its rollout.

Earlier, the California exchange had begun warning insurers that there was a possibility it wouldn't be able to sign up consumers for coverage online at launch. A spokesman for the California exchange said the technology for enrollment is still being tested, and so far tests "haven't revealed any major issue that can't be addressed." The exchange agency will have a clearer picture in the first week of September, he said.