With its common stock hovering at historic highs, Monsanto has outlined several steps to further enhance the value of its shares, including a possible stock split, new incentive and stock option plans for employees, and a stock repurchase program. Investors apparently approve. On March 14, the day plans were announced, Monsanto shares closed at $149⅝, up $4⅝. At press time, the high last week was $158. Shares started 1996 at $122½. Monsanto will ask stockholders at its annual meeting next month to authorize issuance of 650 million additional common stock shares, enabling it to contemplate a possible stock split of 4-for-l or 5-for-l. It is already authorized to issue 200 million common shares and now has about 118 million outstanding. The stock was last split, 2-for-l, in June 1990. New compensation incentive programs for senior management include a premium-price stock option that can only be exercised when certain stockprice targets are reached during a ...