* Hong Kong tech stocks down 7.97% * U.S. S&P futures down 0.22%, European stocks down 0.37% * Bitcoin trading at $37,680 LONDON, July 27 (Reuters) - World stocks fell on Tuesday after investors sold Chinese internet giants for a third straight day, while real U.S. bond yields hit record lows on worries about the economic outlook ahead of a Federal Reserve meeting. The Hang Seng Tech index slid almost 8%, plumbing its lowest since its inception in July 2020 and losing 17% in three days. Big decliners included Meituan and Alibaba , with investors expecting the companies’ food delivery arms to be affected by new regulations guaranteeing workers above minimum pay. Chinese bluechips dropped 3.53%, hitting 2021 lows, thanks to regulatory crackdowns in the education and property sectors. The selling dented previously upbeat stock sentiment elsewhere. European stocks fell 0.37%, moving further away from recent record highs. Britain’s FTSE 100 was down 0.43%. Global stocks fell 0.3%. MSCI’s broadest index of Asia-Pacific shares outside Japan fell 1.94%, hitting its lowest since December. “Valuations are tight but I don’t think the China tech crackdown will lead to a major equities sell-off,” said Christian Lenk, a rates strategist at DZ Bank in Frankfurt. S&P 500 futures dipped 0.22% after all three major U.S. stock indexes closed at record highs for a second straight session on Monday, on optimism ahead of a slew of tech earnings this week. Alphabet Inc, Apple Inc and Microsoft Corp < MSFT.O> are set to publish quarterly results late on Tuesday, with Amazon.com Inc’s due later in the week. POWELL ALERT The Fed begins its two-day meeting on Tuesday, with investors set to scrutinise a statement and press conference from Chair Jerome Powell due late Wednesday. They will be looking to see how the central bank will balance fast-rising prices with the complication of increased coronavirus infections. “There’s a realisation that we have passed the peak of growth,” said Derek Halpenny, head of research at MUFG. “Some of the supply constraints are beginning to ease.” Real, or inflation-adjusted, bond yields across major economies have fallen in recent sessions, a move analysts attribute to growing concern about the economic outlook following an upsurge in COVID-19 variants, as well as technical factors such as hefty bond-buying by central banks. The yield on 10-year Treasury inflation-protected securities (TIPS) hit -1.147% on Tuesday, down about 4 basis points on the day. German inflation-linked bond yields also extended recent falls, hitting a new low at around -1.747%. The yield on benchmark 10-year U.S. Treasury notes slipped 1.8 basis points and 10-year German Bund yields dropped 1.9 basis points, close to a 5-1/2 month low set on Monday. The dollar gained 0.11% against a basket of currencies and the euro dipped 0.1% to $1.1787. The dollar fell 0.23% against the yen. Oil prices inched up as investors bet tight supply and rising vaccination rates will help offset any impact on demand from surging COVID-19 cases worldwide. Brent crude futures rose 18 cents to $74.68 a barrel. U.S. West Texas Intermediate (WTI) crude futures rose 3 cents to $71.94 a barrel. Gold was steady at $1,796.40 per ounce. Bitcoin was trading around $37,600, 0.8% higher on the day. It has recouped some losses after it fell from a Monday peak of $40,581 after Amazon.com offered a qualified denial of a weekend news report that said it was preparing to accept cryptocurrencies. Additional reporting by Sujata Rao in London and Alun John in Hong Kong; Editing by Lincoln Feast, Ana Nicolaci da Costa, Sam Holmes and Joe Bavier Our Standards: The Thomson Reuters Trust Principles.