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A senior official at the National Endowment for the Arts resigned Thursday following an uproar over his participation in a controversial conference call last month that some said encouraged artists to create works supporting President Obama's domestic agenda.

At the same time, White House officials released new guidelines on public outreach meetings, saying the conference call hosted in part by the NEA offered the Obama administration a "teaching moment" on separating policy and politics.

Yosi Sergant, who was director of communications for the NEA until he was reassigned this month in the wake of the controversy, offered his resignation Thursday afternoon, the NEA said in a written statement.

"His resignation has been accepted and is effective immediately," the statement read.

Sergant was one of several officials on an hour-long conference call on Aug. 10 hosted by the NEA, the White House Office of Public Engagement and United We Serve, a nationwide initiative launched by President Obama to increase volunteerism.

The official participants -- including Deputy Director of the White House Office of Public Engagement Buffy Wicks and Michael Skolnik, political director for hip-hop mogul Russell Simmons -- sought focused efforts by the approximately 75 artists on the call to produce works of art that supported the Obama administration's agenda in areas like health care, energy and environment, education and community renewal.

White House officials announced earlier this week that steps would be taken to prevent a recurrence of the call after critics, including one of the artists on the call, labeled it a "well thought-out pitch" to encourage artists to create art on those issues.

The guidelines  were posted Thursday on the White House's blog.

"We should consider this call to be a reminder and a teaching moment," the memorandum reads. "It was organized with the best of intentions to promote community service and volunteerism, something the administration does with many constituencies and something we will continue to do. The misunderstandings that flowed from the call should serve as a lesson going forward of the need to take extra care in planning outreach to ensure it complies with these general principles."

The guidelines, issued by Gregory Craig, counsel to the president, and Norman Eisen, special counsel to the president, suggest organizers "engage only in authorized activities," "avoid even the appearance of impropriety" and "continue to ensure that decisions are merit based."

It adds that "engagement with non-government organizations and citizens should be even-handed."

The guidelines continue, "President Obama has pledged to restore Americans' trust in their government. Strict adherence to the rules is not enough -- we need to avoid even the appearance of politicization in order to ensure people's faith in the actions of the administration."

White House Deputy Press Secretary Bill Burton, who posted the guidelines, added that meetings with the chiefs of staff of the executive branch agencies were held, along with the first of a series of training sessions.

"Though we have made clear that the call was made with the best of intentions and we believe public engagement is an appropriate and vital part of effective governmental functioning, certain comments on the call raised appearance issues that troubled some participants," Burton wrote.

Sergant said on the call that the effort was the first of a "brand new conversation."

He told the artists: "I would encourage you to pick something, whether it's health care, education, the environment, you know, there's four key areas that the corporation has identified as the areas of service. My ask would be to apply artistic, you know, your artistic creative communities' utilities and bring them to the table."

In a statement to FOXNews.com on Tuesday, NEA Chairman Rocco Landesman said Sergant acted "unilaterally and without the approval or authorization" of then-Acting Chairman Patrice Walker Powell regarding the call.

"Some of the language used by the former NEA director of communications was, unfortunately, not appropriate and did not reflect the position of the NEA," Landesman's statement continued. "This employee has been relieved of his duties as director of communications."

Patrick Courrieleche, one of the artists on the call, first wrote about the experience on the blog Big Hollywood. Courrieleche, 39, of Los Angeles, said the ubiquitous Obama "Hope" poster by artist Shepard Fairey and musician will.i.am's "Yes We Can" song and music video were offered as examples of the artist group's clear impact on Obama's landslide election.

"What I heard was a well thought-out pitch to encourage artists to create art on these issues," he told FOXNews.com in August.

FOXNews.com's Joshua Rhett Miller and Stephen Clark contributed to this report.