* Dollar largely flat after reaching four-month high * U.S. Treasury yields dip ahead of auction * Graphic: World FX rates tmsnrt.rs/2RBWI5E (Adds new analyst quote, updates throughout) By Jessica DiNapoli and Elizabeth Howcroft New York, March 25 (Reuters) - The U.S. dollar reached a fresh four-month high before slashing its gains on Thursday, as yields on U.S. Treasuries dipped and investors" appetite for risk shrunk. The dollar index was mostly unchanged at 92.6410 in mid-morning trading. Yields on Treasuries crept down and stocks fell, with 10-year notes yielding 1.598 ahead of an auction on shorter-dated bonds on Thursday. Investors were shrugging off positive U.S. economic data showing that fewer-than-expected Americans filed new claims for unemployment benefits last week. "There"s some nervousness around positioning, some paring down of positions within the foreign exchange market," said Mazen Issa, senior currency analyst at TD Securities, adding that some technical developments have also kept the dollar on a "bit of a roll." U.S. stocks opened lower in a session marked by choppy trading. Concerns about extended lockdowns in Europe also weighed on markets. German Chancellor Angela Merkel"s decision to ditch plans for a lockdown over Easter did little to improve sentiment. The euro was down 0.12% against the dollar, at $1.1800 , with analysts forecasting it could embrace the $1.16 range, as Europe"s economic recovery from the pandemic lags. The Australian and New Zealand dollars, which dropped in the previous two sessions, edged back up slightly against the U.S. dollar, but both were only up by around 0.1% on the day overall. On Wednesday, U.S. Treasury Secretary Janet Yellen and Federal Reserve Chair Jerome Powell expressed their confidence in the U.S. recovery during a second day of testimony to Congress. European leaders meet on Thursday and will discuss vaccine supplies. The EU on Wednesday tightened its oversight of coronavirus vaccine exports, giving it greater scope to block shipments to countries with higher inoculation rates such as Britain. Bitcoin extended recent losses, down 1.43% at $51,535.69 . The cryptocurrency briefly topped $57,000 in the previous session after Tesla Inc boss Elon Musk said customers can now buy the company"s electric cars with the digital token. Currency bid prices at 10:27AM (1427 GMT) Description RIC Last U.S. Close Pct Change YTD Pct High Bid Low Bid Previous Change Session Dollar index 92.6630 92.5970 +0.08% 2.981% +92.7540 +92.5120 Euro/Dollar $1.1801 $1.1815 -0.11% -3.41% +$1.1828 +$1.1791 Dollar/Yen 109.0900 108.6800 +0.40% +5.64% +109.1600 +108.7500 Euro/Yen 128.74 128.42 +0.25% +1.43% +128.9400 +128.4300 Dollar/Swiss 0.9373 0.9358 +0.18% +5.96% +0.9375 +0.9351 Sterling/Dollar $1.3731 $1.3680 +0.38% +0.51% +$1.3741 +$1.3671 Dollar/Canadian 1.2595 1.2582 +0.10% -1.09% +1.2607 +1.2547 Aussie/Dollar $0.7598 $0.7581 +0.28% -1.18% +$0.7614 +$0.7579 Euro/Swiss 1.1060 1.1052 +0.07% +2.34% +1.1070 +1.1043 Euro/Sterling 0.8593 0.8629 -0.42% -3.86% +0.8641 +0.8592 NZ $0.6968 $0.6961 +0.10% -2.97% +$0.6986 +$0.6957 Dollar/Dollar Dollar/Norway 8.6260 8.5685 +0.61% +0.39% +8.6275 +8.5900 Euro/Norway 10.1803 10.1608 +0.19% -2.74% +10.1818 +10.1360 Dollar/Sweden 8.6360 8.6046 +0.18% +5.36% +8.6448 +8.5985 Euro/Sweden 10.1915 10.1733 +0.18% +1.14% +10.1961 +10.1652 (Reporting by Elizabeth Howcroft Editing by Jane Merriman and Paul Simao)