CLS Bank International, which settles about $4.5 trillion in foreign-exchange transactions daily, received a letter from U.S. regulators including it among entities proposed for designation as systemically important, according to a person familiar with the matter.

The London-based bank, which settles transactions in 17 currencies, joins clearinghouses owned by CME Group Inc.; Intercontinental Exchange Inc.; OCC, formerly the Options Clearing Corp.; and the Depository Trust and Clearing Corp. in receiving the designation from the Financial Stability Oversight Council. CLS's inclusion was confirmed by the person, who requested anonymity because the decisions haven't been publicly disclosed.

Being labeled systemically important moves the so-called financial market utilities closer to heightened supervision under the Dodd-Frank Act. The designations are subject to appeal and may be completed “as early as this summer,” said Anthony Coley, a U.S. Treasury Department spokesman.