By Ian Simpson
WASHINGTON, Oct 8 (Reuters) - The Federal Reserve began supplying banks on Tuesday with billions of redesigned $100 bills that incorporate advanced anti-counterfeiting features, the U.S. central bank said.
The notes, which retain the image of American statesman and scientist Benjamin Franklin, include two new security features - a blue three-dimensional security ribbon with images of bells and 100s, and a color-changing bell in an inkwell, the Fed said in a statement.
The $100 bills, the biggest U.S. denomination known in American slang as "Benjamins," also keep security features from the previous design, such as a watermark.
"The new design incorporates security features that make it easier to authenticate, but harder to replicate," said Federal Reserve Board Governor Jerome Powell said in a statement.
U.S. officials have said the $100 note is the most frequently counterfeited denomination of U.S. currency outside the United States due to its broad circulation overseas. In the United States, the $20 bill is the most frequently counterfeited note.
Sonja Danburg, program manager for U.S. currency education at the Fed, said about 3.5 billion new $100 bills had been stockpiled. There are about $900 billion in $100 notes in circulation, with half to two-thirds outside the United States, she said.
The United States has about $1.15 trillion in genuine currency in circulation, and less than 1/100th of 1 percent of that value is counterfeit, Danburg said.
Benjamins are the highest-denominated notes issued by the Federal Reserve since the United States stopped issuing $500, $1,000 and $10,000 notes in 1969.
The new bills have been in development since 2003. The new bills cost about 12.5 cents each to make, 5 cents more than the previous notes because of the greater complexity of the design, Danburg said.
The average $100 bill lasts about 15 years before wearing out and being pulled from circulation. The more frequently handled $1 note lasts about six years, Danburg said.
The Fed said people with old bills did not need to trade them in for new ones since all designs of U.S. currency remained legal tender.