Munich Re, the world’s biggest reinsurer, plans to resume its share buyback after posting a first-quarter profit that beat estimates. The shares fell as the company signaled it may be harder to reach a full-year target. Munich Re will purchase as much as €1bn ($1.27bn) of its own stock by the 2011 annual shareholders’ meeting scheduled for April 20, 2011, it said in a statement today. First-quarter net income rose 11% to €482m, the Munich-based company said separately. The full-year profit forecast, which the reinsurer reiterated last month, has become “increasingly ambitious” following a number of claims from natural disasters.