NEW YORK — A Chinese billionaire who wanted to build a United Nations center in Macau was convicted at his bribery trial on Thursday.

The verdict was returned in Manhattan federal court against Ng Lap Seng, one of China's richest men. Ng was convicted of bribery, conspiracy and money laundering charges.

Ng Lap Seng, a Macau billionaire real estate developer, exits the Manhattan U.S. District Courthouse on October 26, 2015 in New York. File Brendan McDermid / Reuters file

Prosecutors presented evidence that Ng from 2010 to 2015 bribed two U.N. ambassadors with hundreds of thousands of dollars to support his project to build a U.N. conference center, but defense lawyers contended that Ng only paid money when he was asked to spend it to speed the project along.

A prosecutor earlier this week had urged the jury to convict Ng, saying he bribed two United Nations ambassadors so he could build a U.N. facility in China that would be as big as the one in New York, a claim a defense attorney dismissed the case as "a big zero."

"The defendant Ng Lap Seng corrupted the United Nations," Assistant U.S. Attorney Janis Echenberg told the federal court jury on Tuesday during closings at a trial that kept Ng confined under 24-hour guard in a luxury Manhattan apartment for the last two years.

Related: Ex-U.N. General Assembly Head John Ashe Among Six Held in Bribery Scheme

She said the 69-year-old Ng paid millions of dollars to two U.N. ambassadors over a five-year period to clear away red tape so he could build a conference center in Macau that would be the "Geneva of Asia," where tens of thousands of people would spend money at his hotel, a marina, a condominium complex, a heliport and a shopping center.

Echenberg said it was a project that would bring Ng and his family "fame and more fortune."

"Brick by brick, bribe by bribe, the defendant built the path that he thought would build his legacy," she said.

Defense attorney Tai Park raised his voice repeatedly as he derided the prosecution as "frankly outrageous."

Chinese billionaire Ng Lap Seng, left, leaves federal court with his attorney Ben Brafman after he was released on bail in connection with a U.N. bribery scheme on October, 26, 2015 in New York. File Kathy Willens / AP file

"It falls by its own weight," he said. "It's a big zero."

Park reread aloud parts of a U.N. Task Force report that he said proved there were no rules or prohibition against the kind of private-public partnership that Ng had forged with the United Nations and its ambassadors to build a multibillion-dollar facility that would serve developing nations.

He blamed the ambassadors — former U.N. General Assembly President John Ashe and suspended Dominican Republic Ambassador Francis Lorenzo — for abusing their relationships with Ng.

"Mr. Ng literally threw his money in every direction he was asked," Park said.

Related: John Ashe, Ex-U.N. General Assembly President in U.S. Bribery Case, Dies

Ashe, who died last year in an accident at home, had asked Ng to rescue him in 2014 with a $200,000 donation to pay for a concert after another person who was supposed to finance the event backed out, Park said.

He said a $20,000-per-month salary paid to Lorenzo was for his job as president of a media organization meant to benefit developing nations.

Echenberg said if there was any doubt about why Ng was paying Lorenzo a lot of money it was eliminated in December 2012, when he promised him an extra $30,000 monthly to speed approval of the Macau center.

The prosecutor said Lorenzo's testimony was so damaging that Park spent six days on cross-examination.

"You know he's guilty just by the testimony of ambassador Lorenzo," she said.

Lorenzo, who pleaded guilty to accepting and paying bribes, remains free on bail pending sentencing.