Citigroup Inc. (NYSE: C) is encouraging its institutional customers to go paperless.

For every tree not used in the printing of Citi statements, the New York bank said it will invest in 10 seedlings to be planted by the Plant-for-the-Planet Billion Tree Campaign.

The roughly six-year-old charity is responsible for planting more than 12 billion trees since its inception, with the goal of planting a quadrillion total of 1,000 billion trees by 2020, according to a press release.

Citi already offers paperless statements through CitiDirect Online Banking over email or SWIFT.

"Eliminating paper and increasing automation not only leads to greater operational efficiency and control; it also enhances environmental sustainability and delivers cost savings," said Naveed Sultan, Citi's global head of treasury and trade solutions, in the press release. "This is a perfect example of the triple bottom line at work."

Citi said that since the start of last year, its transaction services customers have eliminated roughly seven million pages of paper by enrolling in "paper-free" options. That's the equivalent of almost 1,000 trees.