New York

NEW York's financial regulator has sent subpoenas to Goldman Sachs, Credit Suisse, BNP Paribas and Societe Generale, expanding its probe into the possible rigging of foreign exchange rates through computer programs, people familiar with the matter said.

The state's Department of Financial Services, overseen by superintendent Benjamin Lawsky, is looking at whether algorithms in the banks' electronic trading platforms have been used to front-run or otherwise take advantage of clients, the sources said.