CLB 2019 Proxy Statement

IF YOU PLAN TO ATTEND IN PERSON: Attendance at the meeting is limited to shareholders as of the close of business Eastern Daylight Time on April 25, 2019 (and others with a statutory meeting right), Company management and Company advisors. Registration will begin at 8:00 a.m. CEST and the meeting will begin at 9:00 a.m. CEST on May 23, 2019. Each shareholder desiring to attend MUST bring proof of share ownership as of the “day of registration” (“ dag van registratie” ) as referred to in the Dutch Civil Code (which is April 25, 2019, as described further in the proxy statement) with him/her to the meeting along with a valid form of identification. Examples of proof of share ownership include voting instruction statements from a broker or bank. In addition, you should register with the Company beforehand to indicate your plan to attend. Such registration may be made by contacting the Company's Secretary as described in the proxy statement. Failure to comply with these requirements may preclude you from being admitted to the meeting. It is important that your shares be represented at the annual meeting regardless of whether you plan to attend. In order to be able to vote at the annual shareholder meeting, you will have to be a record holder of shares (or otherwise a person with voting rights with respect to shares) at the close of business Eastern Daylight Time on April 25, 2019. Please mark, sign, date and return the accompanying proxy card accordingly, vote online or vote by phone, all as described in further detail in the proxy statement. If you are present at the annual meeting and wish to do so, you may revoke your proxy and vote in person. By Order of the Board of Supervisory Directors , Jan Willem Sodderland Supervisory Director Amsterdam, the Netherlands March 20, 2019 IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE 2019 ANNUALMEETING OF SHAREHOLDERS TO BE HELD ON MAY 23, 2019 The Notice of 2019Annual Meeting of Shareholders and the Proxy Statement for the 2019Annual Meeting of Shareholders, along with the Company’s Annual Report to Shareholders, is available free of charge at www.proxydocs.com/clb .