AMSTERDAM (Reuters) - Dutch insurer Aegon said on Thursday the company beat analysts' estimates for the first-half, despite a 5% drop in underlying pretax profit to 1.01 billion euros (934.09 million pounds).Analysts polled by the company, which does most of its business in the United States under the Transamerica brand, had predicted core profit to drop to 988 million euros, after the insurer posted a 1.06 billion euros result a year earlier.