Washington  - President-elect Barack Obama said Monday that an internal review showed that his staff did not have "inappropriate" discussions with embattled Illinois Governor Rod Blagojevich about the naming a successor to the Senate.

After Blagojevich's arrest on corruption charges, Obama said last week that he was certain that his own staff did not discuss the vacant Senate seat with Blagojevich or any of the governor's aides, but promised a review of all contacts by his presidential transition team.

"I had no contact with the governor's office, and I had no contact with anybody in the governor's office," Obama told reporters Monday in Chicago. "There was nothing that my office did that was in any way inappropriate or related to the charges that have been brought."

Federal authorities arrested Blagojevich on December 9 at his Chicago home, accusing him of attempting to solicit bribes by using his sole power to appoint a candidate to fill Illinois' US Senate seat, vacated by Obama after he won the presidential election. The 51-year-old governor and his top aide, John Harris, face additional corruption-related charges.

Blagojevich was being wiretapped as part of a long-running federal investigation of his activities in office.

Obama pledged last week to reveal all contacts between his staff and his home-state governor, but said Monday that the US Justice Department had requested that he delay the release by a week because the federal investigation is still underway.

"I do not want to interfere with an ongoing investigation," he said.

Obama has been among the many voices calling on Blagojevich, a fellow Democrat, to resign. Illinois' top law enforcement official has filed a motion asking the state Supreme Court to temporarily suspend Blagojevich's powers.

The Democratic-controlled state legislature has begun taking up impeachment proceedings against Blagojevich and is seeking to change the law to require a special election to replace Obama in the Senate.

In communications intercepted by federal agents, Blagojevich allegedly discussed with aides ways to acquire money or other political favours in return for the Senate appointment.

Obama addressed a question about Blagojevich while announcing cabinet nominations ahead of his January 20 inauguration. The president-elect named Steven Chu, a Nobel Prize-winning physicist and leading voice on alternative energy, to head the Energy Department.

Lisa Jackson, the New Jersey governor's chief of staff and a former leader of the state's climate policy, was picked to head the Environmental Protection Agency (EPA), and Carol Browner, who led the EPA under Bill Clinton, will take a new White House position coordinating climate and energy policy. (dpa)