Donaldson, Lufkin & Jenrette closed DLJ Investment Partners II, a $1.6 billion mezzanine investment fund believed to be the largest of its type. Investors include the $40.9 billion State Board of Minnesota, St. Paul, which has committed up to $75 million to the fund. Over time DLJ intends to borrow an additional $400 million to add leverage. The fund, which will be managed by an affiliate of DLJ Merchant Banking, will invest in debt and preferred stock in leveraged acquisitions and growth financing for public and private companies and off-balance-sheet special situations. Average investments are expected to range between $25 million and $250 million.