Syngenta (SYNN.VX) has said a $2 billion break-up fee that unwanted U.S. suitor Monsanto (MON.N) has pledged to pay if its proposed $45 billion merger failed would only apply in limited cases, leaving its shareholders exposed to the bulk of regulatory risks. Swiss Syngenta, the world’s largest maker of farming pesticides, told Reuters that based on its legal interpretation of Monsanto’s proposal, the payment would only be triggered if so-called horizontal antitrust concerns were to trip up the deal. Monsanto has rejected this interpretation.