NEW YORK, Oct 9 (Reuters) - Investors in U.S.-based mutual funds pulled $3.4 billion out of stock funds in the latest week amid concerns over the U.S. government shutdown and whether the U.S. debt ceiling will be raised, data from the Investment Company Institute showed Wednesday. The outflows from stock funds in the week ended Oct. 2 marked a second straight week of withdrawals, according to data from ICI, a U.S. mutual fund trade organization. During the preceding week, investors pulled $3.7 billion from the funds. Global stock markets fell ahead of the U.S. government shutdown on Oct. 1, which was the first in 17 years. Worries also grew ahead of a looming dispute between Democratic and Republican lawmakers about raising the U.S. debt ceiling. MSCI's world equity index fell 0.3 percent over the weekly reporting period, while the benchmark Standard & Poor's 500 rose a slight 0.1 percent. Despite the slight gain in the S&P 500, investors pulled $4.1 billion from funds that hold U.S. stocks in the latest week, up modestly from the prior week's outflows of $3.9 billion. The outflows from U.S.-focused stock funds were the biggest since the start of the year, according to ICI data. Funds that hold non-U.S. stocks, meanwhile, attracted a modest $739 million in new cash. Investors also pulled $400 million from bond funds in the latest week, reversing the prior week's inflows of $1.2 billion, according to ICI data. Taxable bond funds attracted modest inflows of $468 million, while municipal bond funds had outflows of $868 million. The net outflows occurred even as the yield on the benchmark 10-year U.S. Treasury note fell about 1 basis point to 2.62 percent over the weekly period. Bond yields move inversely to their prices. Investors also pulled $114 million from hybrid funds, which can invest in both stocks and fixed income securities. The outflows were the first since late June, according to ICI data. The following table shows estimated ICI flows for the past five weeks (all figures in millions of dollars): 9/4/13 9/11/13 9/18/2013 9/25/2013 10/2/2013 Total Equity 905 5,236 3,392 -3,703 -3,387 Domestic -697 2,470 44 -3,888 -4,126 World 1,602 2,766 3,347 185 739 Hybrid* 349 1,282 1,519 1,318 -114 Total Bond -6,757 -5,511 -2,643 1,204 -400 Taxable -4,710 -2,805 -895 1,493 468 Municipal -2,048 -2,706 -1,748 -289 -868 Total -5,503 1,007 2,268 -1,181 -3,901 *Hybrid funds can invest in stocks and/or fixed income securities.