C Citigroup Inc

   By Christina Rexrode 
 

Citigroup Inc. is expected to lose more than $150 million due to the wild swings in Switzerland's currency, according to a person familiar with the matter.

The New York firm's currency-trading desk is among those that incurred sizable losses after the Swiss National Bank unexpectedly removed the cap on the Swiss franc's value.

Citigroup is also one of the biggest prime brokerages for FXCM Inc., the foreign-exchange broker that is trying to shore up its capital with a potential rescue package involving Jefferies Group LLC, according to a person familiar with the matter.

On Friday afternoon, Citigroup and other brokers were waiting to see if the Jefferies rescue would go through. The brokers were holding informal talks about what they might do if that rescue plan falls apart, the person said.

A Citigroup spokesman declined to comment.

Write to Christina Rexrode at christina.rexrode@wsj.com