Talks are ongoing and the total penalty, negotiated by multiple U.S. agencies, could change. A second source described the current settlement as in the "high hundreds of millions" and suggested it could reach $1 billion.
The bank, France's third-largest listed lender, is expected to reach an accord as soon as this month, the two people said.
A spokeswoman for Credit Agricole had no immediate comment.
Last month, Credit Agricole said it was in "very advanced talks" with U.S. authorities over the sanctions probes and it expected to reach a global settlement in autumn. It set aside an additional 350 million euros ($392 million) for a settlement.
In total, Credit Agricole has earmarked 1.6 billion euros ($1.79 billion) for litigation, but it is unclear how much of that is dedicated to a deal on sanctions.
The resolution focuses on misconduct that occurred between 2003 and 2008, one source said.
The sources did not want to be identified because negotiations are still underway.
Settlements with U.S. authorities over sanctions typically take longer to complete than anticipated, in part because so many agencies are involved, including the U.S. Department of Justice, Treasury Department, Federal Reserve, Manhattan District Attorney's office and New York's Department of Financial Services. All declined to comment on the Credit Agricole negotiations.
About a dozen international banks, mostly European, have been stung by U.S. penalties for sanctions-busting totaling nearly $14 billion since 2009.
In March, Commerzbank AG, Germany's No. 2 lender, agreed to pay $1.45 billion.
Italy's UniCredit SpA, France's Societe Generale, and Germany's Deutsche Bank AG are still under investigation, sources have told Reuters.
BNP Paribas, France's largest bank, last year paid a record-breaking $8.9 billion and pleaded guilty to criminal charges over its sanctions-busting. It also was banned from conducting certain U.S. dollar transactions for a year.
In most cases, authorities have struck agreements with the banks to defer criminal charges as long as the lender abides by the terms of the deal.
But even if such a deal is struck between prosecutors and Credit Agricole, it may not be home free.
Standard Chartered Plc's 2012 deferred prosecution agreement was extended in December for another three years amid an ongoing probe of Iranian-controlled companies banking in Dubai, sources have told Reuters.
($1 = 0.8936 euros)
By Karen Freifeld