Sparrow is a partner at the law firm Ashurst LLP, Petrofac said in a statement.
The SFO said in May it had begun an investigation into the activities of Petrofac and its subsidiaries in connection with a probe into Monaco-based Unaoil.
Petrofac had said in May that it would set up a committee responsible for responding to the investigation, comprising its chairman, CFO and independent non-executive directors, and would also hire an senior external specialist to review its compliance processes.
The company also said on Wednesday it had set up a new committee for overseeing the company's compliance and ethics.
The committee comprises of three non-executive directors, George Pierson as the committee's chairman, Andrea Abt and Matthias Bichsel
(Reporting by Justin George Varghese in Bengaluru. Editing by Jane Merriman)