Nisa Investment Advisors LLC lowered its holdings in United Airlines Holdings, Inc. (NASDAQ:UAL – Get Rating) by 62.7% in the 1st quarter, according to the company in its most recent 13F filing with the SEC. The institutional investor owned 23,101 shares of the transportation company’s stock after selling 38,900 shares during the quarter. Nisa Investment Advisors LLC’s holdings in United Airlines were worth $1,071,000 at the end of the most recent reporting…