BANCROFT <BCV> SHAREHOLDERS REBUKE ZICO OFFER Bancroft Convertible Fund Inc, the target of an unfriendly cash offer by <Zico Investment Holdings Inc>, said its shareholders approved proposals requiring a 66-2/3 pct affirmative vote of all outstanding shares before fundamental changes in its status could be made. Previously, only a simple majority of outstanding shares was needed to change Bancroft's investment status from a diversified to a non-diversified fund, among other things. Bancroft said its board continues to recommend that stockholders not tender their shares to Zico, a British Virgin Islands company which it said had ties to South Africa.