Rule 2.10 Announcement

Aon plc - Rule 2.10 Announcement - Relevant Securities in Issue

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, DIRECTLY OR INDIRECTLY (IN WHOLE OR IN PART) IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION

LONDON, U.K, May 4, 2021 -- In accordance with Rule 2.10 of the Irish Takeover Panel Act, 1997, Takeover Rules 2013, Aon plc (“Aon”) confirms that, as of the close of business on April 30, 2021, Aon’s issued share capital, excluding treasury shares, consisted of 225,630,496 Class A ordinary shares, $0.01 nominal value per share (“Aon Shares”). Aon Shares are traded on the NYSE under the symbol AON. The International Securities Identification Number (ISIN) of the Aon Shares is IE00BLP1HW54.

Aon confirms that, as of the close of business on April 30, 2021, there were outstanding 0 options (the “Stock Options”), 3,203,020 time-based vesting restricted stock units (the “RSUs”) and 1,285,997 performance-based vesting restricted stock units (the “PSUs”). Upon exercise, each Stock Option entitles the holder to purchase one Aon Share at the applicable exercise price. Upon vesting, each RSU and PSU entitles the holder to receive one Aon Share.

The Directors of Aon plc accept responsibility for the information contained in this announcement. To the best of their knowledge and belief (having taken all reasonable care to ensure such is the case), the information contained in this announcement is in accordance with the facts and does not omit anything likely to affect the import of such information.

Any holder of 1% or more of any class of relevant securities of Aon plc may have disclosure obligations under Rule 8.3 of the Irish Takeover Panel Act, 1997, Takeover Rules 2013.