Total U.S. money market mutual fund assets fell by $17.7 billion to $2.61 trillion for the week that ended Wednesday, according to the Investment Company Institute.

Assets in the nation’s retail money market mutual funds fell by $4.5 billion to $918.26 billion, the Washington-based mutual fund trade group said Thursday. Assets of taxable money market funds in the retail category fell $3.6 billion to $724.28 billion. Tax-exempt retail fund assets fell $860 million to $193.98 billion.