By Nate Raymond

NEW YORK (Reuters) - The former head of a New York-based foundation was sentenced on Friday to 20 months in prison for participating in a scheme to pay hundreds of thousands of dollars in bribes to a former U.N. General Assembly president.

Sheri Yan, Global Sustainability Foundation's former chief executive, was sentenced by U.S. District Judge Vernon Broderick in Manhattan after pleading guilty in January to passing bribes to John Ashe, the former General Assembly president.

Broderick, who also fined her $12,500 and ordered her to forfeit $300,000, said that because of her crimes, "there was substantial damage done to the U.N. itself and the image of the U.N."

"There's no question this crime was a serious offense," he said.

Yan, 60, is one of seven people who was charged since October in connection with bribes paid to Ashe, a former U.N. ambassador from Antigua and Barbuda who was General Assembly president from 2013 to 2014.

Prosecutors said Ashe, who died in June awaiting trial, took over $1.3 million in bribes from Chinese businessmen, including Macau billionaire real estate developer Ng Lap Seng, to promote their interests within the United Nations and Antigua.

Those bribes included over $800,000 largely from three Chinese businessmen that was paid through Yan and her foundation's former finance director, Heidi Hong Piao, prosecutors said.

The businessmen included a media executive wanting to invest in Antigua, a security technology executive seeking a contract with the Caribbean nation and a real estate developer who wanted Ashe to appear at a conference, prosecutors said.

Yan also paid Ashe $20,000 a month to serve as honorary chairman of her foundation, and covered the costs of custom suits and clothing for him, prosecutors said.

In return, Yan received diplomatic appointments from Ashe, which she used to promote the foundation, which she established after working as co-CEO of a company called eChina Cash, prosecutors said.

"What she chose to do was cheat for herself and her co-conspirators," Assistant U.S. Attorney Daniel Richenthal said.

In court, Yan, who immigrated from China in 1987 with just $400, blamed her actions a desire to prove that she was important and a focus on her "artificial status."

"I will forever punish myself," she said, weeping. "I'm very, very sorry."

Two other defendants have pleaded guilty, including Piao. A Jan. 23 trial is scheduled for Ng and his assistant, Jeff Yin, on charges that they paid Ashe over $500,000 in bribes.

(Reporting by Nate Raymond in New York; Editing by Bernard Orr)