The same lack of oversight that enabled traders to manipulate the London interbank offered rate plagues other benchmarks around the globe, according to a group of international securities regulators.

Fewer than half of the benchmark interest rates surveyed in the U.S., Europe and Asia were based on actual transactions, according to a confidential International Organization of Securities Commissions discussion paper obtained by Bloomberg News. Instead, the rates were calculated by methodologies that were unclear, not transparent and only rarely subject to specific regulatory standards or obligations, the group said.

"Iosco, as the international organization of financial market regulators, is firmly committed to restoring confidence in benchmarking activities globally," Masamichi Kono, chairman of the Iosco board, said in a Sept. 14 statement.