Principal Financial Group announced today it has closed on its previously announced acquisition of Wells Fargo & Co.’s Institutional Retirement & Trust business. Des Moines-based Principal will now begin the integration of Wells Fargo’s defined contribution, defined benefit, executive deferred compensation, employee stock ownership plans, institutional trust and custody, and institutional asset advisory businesses. The $1.2 billion acquisition doubles the size of Principal’s U.S. retirement offerings. “As a top-three leader in the U.S. retirement industry, we will be well-positioned to invest and grow our business to the benefit of our customers, employees and shareholders, Principal Chairman, President and CEO Dan Houston said.