Aon plunges after Q1 profit, revenue miss estimates

** Shares of insurance broker Aon AON fall ~10% to $275.70 in morning trading

** Aon reports Q1 profit of $5.66, missing estimates of $5.91, according to LSEG data

** Revenue of $4.07 bln in Q1 also falls short of Street expectations of $4.13 bln

** "Retail brokerage revenue growth included "solid" growth in EMEA, Asia, and the Pacific. But U.S. results faced pressure from lower net new business and the ongoing impacts from external capital markets activity," write analysts at TD Cowen

** Stock down ~5% YTD including session moves