His former girlfriend, Tamika Riley, was convicted on those charges and the eight others she faced, including evading taxes and cheating to obtain subsidized housing assistance for herself.
Both remain free on bail. Sentencing was set for July 29.
James could face seven to eight years in prison, but a judge could impose a much stiffer penalty - as much as 20 years on some individual counts. Riley faces similiar exposure. James could also be stripped of pensions that provide a six-figure annual income.
The jury deliberated for about 30 hours over six days at a courthouse just a block from City Hall, where James led New Jersey's largest city for 20 years until 2006.
Neither James nor Riley showed any emotion as the jury foreman spoke the word "guilty" 22 times.
Attorneys for both James and Riley said they would appeal.
"Tamika is deeply disappointed with the verdict," said her lawyer, Gerald Krovatin.
An expressionless James left the courtroom without speaking to reporters and left the building through a back entrance. His lawyer declined comment, except to say James would appeal.
As he reached the building's lobby and exited the elevator, his wife approached him and he kissed her on the cheek before they left together.
Riley, 39, was a publicist who once ran a clothing boutique near City Hall, where James, 72, led the state's largest city from 1986 to 2006. He was also a Democratic state senator from 1999 to January 2008.
Prosecutors charged that James abused his office and betrayed his constituents by arranging for the sale of nine city-owned properties for $46,000 to Riley from 2001 to 2005. Riley quickly sold them for $665,000 without ever starting required rehabilitation work on most of them, prosecutors said.
James' defense attorneys argued that no evidence showed that the mayor assisted Riley or even had knowledge of her transactions, and that the mayor's interest in redeveloping the struggling city was well within the scope of his duties.
They stressed that the Newark City Council, not the mayor, had final approval over the land prices and sales. James' team presented only two witnesses, both members of the council, who said James never tried to influence their decisions.
Riley lawyer Gerald Krovatin blamed Riley's real estate lawyers for failing to protect her from missteps in the land deals.
He said she got no special treatment because of her affair with James, a married man twice her age, and claimed she was swept up in the investigation of James only because of their "intimate" relationship.
Krovatin told the jury that the affair lasted just six months, ending in the fall 2002. Prosecutors suggested the affair lasted several years, with one witness saying it started around 2000 and went to 2006.
Neither James nor Riley testified during the trial, which had five weeks of testimony from 40 witnesses.
Jurors got some sense of the power James wielded in the city and the state, and learned that he had a home on the Jersey shore and a series of yachts - possessions that had long raised eyebrows around the state.
They did not hear about his last mayoral election, in 2002, when he defeated the current mayor, Cory A. Booker, in a bitter campaign chronicled in the Oscar-nominated documentary film "Street Fight."
James is one of the most powerful figures snared in a series of corruption cases in New Jersey brought by the U.S. Attorney's Office, but one of the few to plead not guilty.
James still faces a federal trial on charges he used city-issued credit cards to pay for $58,000 worth of personal expenses while he was mayor, including trips with several women other than his wife, to Martha's Vineyard, Puerto Rico, the Dominican Republic and Rio de Janeiro.
Stay with Eyewitness News and 7online.com for more on this developing story.
