Marlboro Man Shopping for Asthma Drugs Puts Investors in a Bind

The battle for control of Vectura Group Plc has put shareholders and the board in a bind, forced to decide if the highest bidder for the U.K. health care company is also the best owner.

It’s a dilemma thrown up by the nature of the two suitors. After private-equity firm Carlyle Group Inc. made the first foray, tobacco giant Philip Morris International Inc. jumped into the fray with a higher bid. A round of back-and-forth increases has given Philip Morris the upper hand on price, while Carlyle maintains that it’s a more suitable parent than a seller of cigarettes.

As ...