By Junko Fujita

TOKYO, Dec 27 (Reuters) - U.S. asset manager Fortress Investment Group LLC aims to raise 200 billion yen ($1.9 billion) to set up Japan's first infrastructure fund, three people with knowledge of the matter told Reuters on Friday.

Fortress plans to invest in roads, airports and other infrastructure with money pooled in the Fortress Japan Income Fund, said the people who declined to be named as they are not authorized to speak to the media.

Fortress officials in Tokyo declined to comment.

The government in the past few years has been working toward selling rights to operate public assets such as roads and airports to reduce debt.

That pledge gained new impetus this year after the government revised laws to allow the sale of rights to operate airports.

The process of selling the right to operate Sendai Airport, which was damaged by the March 2011 earthquake, to public investors as early as next year is underway.

The sale of rights to operate New Kansai International Airport and Osaka International Airport is also being planned. The government in 2011 passed a law allowing New Kansai International Airport Co, which is saddled with 1.2 trillion yen in debt, to sell the rights as early as 2014.

Infrastructure could be an attractive alternative investment for Japan's pension funds which are heavily weighted in Japanese government bonds, the people said.

The Government Pension Investment Fund, the world's largest public pension fund, will join Canada's OMERS in investing in infrastructure abroad to diversify its portfolio, people familiar with the matter told Reuters earlier this month.

Fortress is known in Japan as an investor in distressed assets, which it obtains by buying underlying debt at a discount. It aims for its new fund to provide more stable, long-term returns, the people said.