Obama under fire as Americans lose prior health plans

* Clamor over canceled plans joins website problems

* Older health plans often fail to meet new standards

* Health Secretary Sebelius to testify Wednesday

By Roberta Rampton

WASHINGTON, Oct 29 (Reuters) - President Barack Obama is facing fresh attacks for his pledge that Americans who like their current healthcare plans can keep them under Obamacare after reports that thousands of Americans facing cancellation notices.

Accusations that the pledge was misleading are potentially a deeper threat to Obama than the website glitches that have plagued Healthcare.gov since its Oct. 1 launch and allowed only a trickle of people to sign up on new federal insurance exchanges.

Another technical problem struck on Tuesday evening as Connecticut's health exchange said the federal data hub that serves it as well as Healthcare.gov was "experiencing an outage" - for the second time in three days. A similar outage on Sunday also halted enrollment on Healthcare.gov.

Obama has downplayed the problems with the website, saying it's like a cash register not working, and has stressed that the underlying product of the 2010 Affordable Care Act is "actually really good."

But critics of Obamacare have seized on the hundreds of thousands of Americans due to lose their current plans because they fail to include essential benefits required by the law and are asking whether Obama misrepresented the law.

"Can you understand the level of frustration and concern about what many Americans perceive to be a false claim from the administration?" asked Representative Peter Roskam, an Illinois Republican, during a House oversight hearing on Tuesday featuring Marilyn Tavenner, a top U.S. official overseeing the law's rollout.

Tavenner, the administrator of the U.S. Centers for Medicare and Medicaid Services (CMS), apologized for problems with Healthcare.gov but quickly came under fire about the Americans losing their current coverage plans.

Hours after Tavenner testified, the House Oversight and Government Reform Committee released a Sept. 6 status report from Obamacare contractor CGI Federal that warned of potentially severe performance risks less than a month before the rollout. The report was dated four days before CGI and other contractors told Congress the project was on schedule to open.

Health and Human Services Secretary Kathleen Sebelius, who has faced Republican calls for her resignation, is scheduled to testify before another House panel on Wednesday and will likely confront similar questions about whether the administration misled the public about the benefits of Obamacare.