SAO PAULO, Jan 21 (Reuters) - Brazilian agricultural firm Andre Maggi Participacoes SA (Amaggi) on Thursday priced a $750 million green bond with proceeds earmarked for clean energy projects and responsible grain origination.

Some $500 million of the proceeds will be used on new ventures while $250 million will refinance debt tied to initiatives such as buying and processing certified soybeans, Chief Financial Officar Dante Pozzi said in a phone interview.

The 2028 notes yielding 5.25% are part of a recent boom in green bonds, which exclude sectors deemed to be unethical or polluting. It is also Amaggi's first issuance in the dollar bond market.

"We had to take investors by the hand," Pozzi said of the four-day meeting rounds to sell the deal. "Our industry is not very well known."

The company, owned by the family of former Agriculture Minister Blairo Maggi, was Brazil's fifth largest exporter of soybeans and soy products in 2020, according to shipping data.

Investment research firm Lucror Analytics recognized Amaggi's commitment to environmentally and socially responsible practices. But lead analyst Soummo Mukherjee raised concerns in a Wednesday note about governance risks tied to Amaggi's family ownership. He also flagged allegations from environmental groups about deforestation on land converted into soy farms.

"We created a structure and our processes evolved a lot," Pozzi said, when asked about those concerns. "This is recognized by those who finance the company."

Pozzi said the Amaggi family is barred from executive roles and the bond's sustainability framework involves a commitment to invest, train and partner with sustainable soy farmers.

Amaggi produces grains on nearly 170,000 hectares of arable land, owns logistics facilities in key grain states and also operates five small hydroelectric power plants.

Brazilian sugar and meat producers have long tapped bond markets, but the country's grains producers rarely do so. (Reporting by Ana Mano; editing by Diane Craft)