Bear Stearns ( BSC) employees have benefited as much as anyone from the brokerage's high-flying stock. Now the company is opening its wallet to prevent their divestitures from diluting the market. The big Wall Street firm today authorized a new $1 billion common stock buyback, mainly to offset the potentially dilutive impact of stock sales by Bear employees. A day after Bear reported strong fourth-quarter earnings last month, Bear's top managers filed registration statements to sell thousands of shares. Other lower-level employees have also been sellers. Like many Wall Street firms, Bear rewards top employees with grants of restricted stock. With Bear's shares currently selling around $102, the restricted stock grants represent an additional lucrative perk to the securities firm's employees. The buyback program is meant to replenish an earlier $1 billion share repurchase plan, under which Bear acquired $623 million shares. In late-day trading, shares of Bear were up $1.40, or 1.4%, to $102.75.