Ebbers had argued the judge or prosecutors should have granted immunity to three witnesses that Ebbers contends could have helped clear him of charges related to the fraud.
His lawyers also said prosecutors unfairly prejudiced jurors by suggesting in their closing statement that there was evidence outside the trial record that proved government witnesses were telling the truth.
"I find that none of these grounds requires a new trial," Judge Barbara Jones wrote in a ruling made public Tuesday.
Ebbers' lawyers had sought the testimony of the three witnesses — former WorldCom executives — Ron Beaumont, Ron Lomenzo and Stephanie Scott — but each invoked their Fifth Amendment right and did not testify.
"Defendant fails to show that the government has used immunity to gain a tactical advantage over him, or that the testimony of Beaumont, Lomenzo or Scott would be exculpatory," Jones wrote.
Jones also noted that she had instructed jurors to disregard the remark in the prosecution closing argument.
"Considering the heft of the evidence, it is extraordinarily unlikely that one oblique comment by the government at the end of a lengthy, detailed summation could have made any difference in the jury's ultimate decision to convict," she wrote.
Ebbers' lawyers had also argued Jones unfairly told jurors they could find him guilty based on "conscious avoidance," which they said allowed jurors to convict Ebbers because he "should have known" about the fraud.
The ruling by Jones means Ebbers' sentencing hearing will go forward Wednesday morning.
In papers filed last month, federal prosecutors asked Jones to follow a probation report that calculated Ebbers' crimes under federal sentencing guidelines and suggested he receive a life sentence.
The prosecutors also noted that Adelphia Communications Corp. (search) founder John Rigas (search), 80 and in poor health, received a 15-year sentence last month — amounting to a life term — for his role in the fraud at that company.
"The enormity of the crimes that Ebbers committed cannot be overstated: The fraud at WorldCom was the largest securities fraud in history," prosecutors wrote, noting the name WorldCom is now "synonymous with fraud."
Still, a Supreme Court ruling earlier this year made the sentencing guidelines only advisory for federal judges, not mandatory, giving Jones far greater flexibility in determining Ebbers' penalty.
For his part, the 63-year-old former CEO has asked for a term "substantially below" life in prison, citing his poor health and a history of charitable works. More than 100 people have also written to Jones on his behalf.
Jones has ruled Ebbers will be allowed to present witnesses at the sentencing to testify to his character and his medical condition, plus an expert witness to discuss the amount of money lost in the WorldCom scandal.
The sentencing will be the back end of an extremely damaging week for Ebbers, once known as a swaggering and successful CEO as WorldCom grew ever larger in the late 1990s.
On Monday, another judge gave preliminary approval to a settlement under which Ebbers must forfeit almost all his personal assets, including $5 million cash up front, to resolve a shareholder lawsuit.
That settlement will leave Ebbers' wife with about $50,000 of Ebbers' assets and a modest home in Jackson, Miss. A far more lavish family home in Brookhaven, Miss., will be sold off as part of the settlement.
WorldCom collapsed into bankruptcy in 2002, and investigators eventually uncovered $11 billion in fraud — much of it because accountants were classifying regular expenses as long-term capital expenditures. The company has since re-emerged under the name MCI.
After Ebbers is sentenced, five more former company executives and accountants who pleaded guilty in the fraud will face sentencing later this summer.