(Adds details on funds, table) By Trevor Hunnicutt NEW YORK, Dec 13 (Reuters) - Investors pulled record cash from U.S.-based stock funds and pulled billions more from bonds in a week of escalated caution, Lipper data showed on Thursday.

More than $46 billion thundered out of U.S. stock mutual funds and exchange-traded funds (ETFs), the most ever, while a near-record $13 billion poured from bonds, according to the research service. Relatively low-risk money market funds pulled in $81 billion, also the most on record, the research service's data showed.

The withdrawals show cracks developing in investor confidence in the waning days of a wild year of up-and-down trading that has left many people with losses across both stock and bond funds, a rare occurrence.

In addition to U.S. Federal Reserve rate hikes, investors have been worried about excessive corporate borrowing, rising relative yields on short-term bonds, U.S.-China trade tensions and slowing growth in corporate profits. The average U.S.-based equity fund is down 6.3 percent through Dec. 11, and its bond counterpart is down 0.9 percent, Lipper said.

More than $45 billion of the withdrawals came from equity mutual funds during an end-of-year period typically marked by major turnover as investors re-evaluate their holdings for tax reasons and other purposes, though typically not with this amount of volume in a single week.

Lipper's data measures a week as the seven-day period from Thursday to Wednesday, and most of its data dates back to 1992.

The following table shows estimated ICI flows for mutual funds and ETFs (all figures in millions of dollars): Sector Flow Chg % Assets Assets Count ($blns) ($blns) All Equity Funds -46.177 -0.67 6,740.688 11,972 Domestic Equities -35.980 -0.73 4,813.595 8,511 Non-Domestic Equities -10.197 -0.52 1,927.093 3,461 All Taxable Bond Funds -13.398 -0.49 2,726.414 5,919 All Money Market Funds 81.222 3.48 2,417.212 966 All Municipal Bond Funds -0.317 -0.08 420.080 1,426 (Reporting by Trevor Hunnicutt in New York Editing by Leslie Adler and Matthew Lewis)