For more than a year, PHA has operated under the control of HUD. Kelly, who previously worked for the New York City Housing Authority, began instituting reforms, including a strict ethics policy that took effect Friday.
Kelly did not reply to e-mails or calls for comment.
In a news release, Mayor Vincent C. Gray of Washington said the hiring of Kelly was an effort to sharpen his administration's focus on the district's need for affordable housing. In his new post, Kelly will earn $165,000, compared with $225,000 at PHA.
Kelly maintains a home in Washington and was director of the District of Columbia Housing Authority from 2000 to 2009. After announcing his resignation at Friday's PHA board meeting, Kelly said only that he was leaving for "personal reasons."
In another PHA issue, Greene has lost the latest round in his battle to block the release of invoices from law firms that worked for the agency during his tenure.
In a decision this month, the U.S. Court of Appeals for the Third Circuit rejected Greene's appeal — which has dragged for the last year.
The former PHA chief had argued that the legal bills might contain information protected by lawyer-client confidentiality, but PHA had a team of researchers review the bills for months and it determined that they did not contain material covered by lawyer-client privilege.
"Greene's assertion of possible privileged material included in the law firm invoices is based entirely on speculation," Judge Thomas Vanaskie wrote.
Contact Jennifer Lin at 215-854-5659 or jlin@phillynews.com, or follow on Twitter @j_linq.