Lorenzo was arrested in early October, linked to a bribery scandal that also snared former General Assembly President John Ashe and rocked the United Nations
. He faces a maximum of 63 years in prison though his sentence will likely not be that long.
Lorenzo,a major name in U.N. political and social circles, pleaded guilty to bribery, conspiracy to commit bribery, money laundering, tax fraud and illegal bank accounts.
His attorney, Brian Bieber, said his client "has chosen to plead guilty and accept responsibility for his criminal conduct."
In court, Lorenzo agreed with government charges that he had helped channel bribes from Chinese businessmen to Ashe, who would then allegedly seek to use his offices to help set up a conference center in Macau.
Ashe and Chinese businessman Ng Lap Seng, a Macau business developer, have pleaded not guilty.
Three of the other original defendants have now changed their pleas to guilty.
After Wednesday's court session, attorneys for Ng said Lorenzo's guilty plea in no way affects their clients case.
Ng strongly maintains his innocence, according to his attorneys, Benjamin Brafman and Hugh Mo.
Asked how Lorenzo's guilty plea would affect the other defendants, Bieber said, "You heard in open court that Mr. Lorenzo has accepted full responsibility for his individual conduct as well as his conduct committed in agreement with his co-defendants."
Lorenzo declined to comment as he was pursued through the downtown streets by news cameras.
In court, the government indicated Lorenzo also participated in assisting unnamed foreign officials. When Ashe was arrested, he was accused of using bribe money in Antigua with senior Antiguan government officials, including the country's former prime minister.
The United Nations is conducting its own audit after the high-profile arrests.