The UK Serious Fraud Office has closed a three-year bribery and corruption investigation into the British subsidiaries of Swiss engineering company ABB, it said on Tuesday.
The investigator and prosecutor has said its inquiry into the activities of the ABB units, their officers, employees and agents was related to its probe into the activities of Monaco-based oil and gas consultancy Unaoil.
"After a thorough and detailed review of the available evidence, the SFO has concluded that this case did not meet the relevant test for prosecution...," the SFO said in a statement.
ABB was not immediately available for comment.
The SFO only proceeds with criminal investigations if the evidence supports a realistic prospect of conviction and if the prosecution is in the public interest.
(Reporting by Kirstin Ridley, editing by Louise Heavens)