Résumé : We study
exponential Levy models with stochastic dividends changing the
intensity at some random time. As well known, exponential Lévy models
in general, and our models with stochastic dividends in particular,
lead to incomplete market. Moreover, we can have tree levels of
information about stochastic dividends, corresponding to different
filtrations: natural, or enlarged progressively, or enlarged
initially.We propose to use utility maximisation approach and the
duality to price and to hedge in such situation. We will restrict
ourselves to classical HARA utilities and we will derive pricing
formulas and the expressions for utility maximising strategies for tree
different filtrations mentioned above.