The Wall Street Journal announced last Friday that Fortress Investment Group (FIG) has re-opened its infrastructure fund, Fortress Worldwide Transportation and Infrastructure Investors Fund, to raise an additional $600 million by the end of the month.

The publicly-traded investment firm had initially closed on $395 million in commitments in January 2013, according to investment documents from the San Bernardino Country Employees' Retirement Association.

Fortress plans to continue using the fund to invest in infrastructure and equipment related to rail, airport, port, energy and telecommunications assets.

On January 3rd, 2014, Fortress submitted a preliminary prospectus to the US Securities and Exchange Commission announcing a $100 million IPO of its infrastructure fund. The document showed that the IPO would be underwritten by Barclays and Deutsche Bank Securities. However, the IPO finally did not take place.

According to the source, the new fundraising efforts could be linked to the potential IPO of the unit.

The fund had invested $309 million as of the end of 2013, with a net internal rate of return of 12%.

The San Bernardino Country Employees' Retirement Association opted to commit $50 million to the fund, in spite of recognizing certain risks associated to with the fund's planned IPO, such as increased volatility from market exposure and daily pricing.