CAPITAL BANCORP <CAPB> SEES GAIN ON UNIT SALE Capitol Bancorp said it has sold its 80 pct interest in CAP Mortgage Co Inc for 3.1 mln dlrs, adding this is expected to result in an after tax gain of about 900,000 dlrs to be reported in the first quarter. Capitol Bancorp said the CAP Mortgage interest was sold to Michael M. Bronstein, president of CAP Mortgage, and Robert Fox, president of Fox Properties Inc. Bronstein already held the other 20 pct of CAP Mortgage's stock.