(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window.)
* Fed decision at 1800 GMT
* Alphabet, Boeing jump after strong earnings
* Apple slips on glum revenue forecast
* Indexes: Nasdaq up 0.64%, S&P up 0.07%, Dow off 0.16% (Updates to early afternoon)
By Sagarika Jaisinghani and Sruthi Shankar
July 28 (Reuters) - The technology-heavy Nasdaq rose on Wednesday on strong earnings from Google-parent Alphabet, as investors turned to the Federal Reserve to gauge the impact of rising inflation and the Delta variant on its monetary stimulus.
Alphabet Inc shares rose 3.8% to an all-time high as a surge in advertising spending helped it post record quarterly results, although the Nasdaq's gains were capped by a forecast of slowing revenue growth from Apple Inc.
Wall Street's main indexes have scaled record highs this month on hopes of stellar corporate results amid a broader economic recovery, but the pace of gains has slowed recently due to a deepening regulatory crackdown in China and fears of a quicker-than-expected tapering of monetary policy.
All eyes on Wednesday will be on the outcome of the Fed's two-day meeting, with investors looking for comments on how the double whammy of rising inflation and a spike in COVID-19 cases would impact the central bank's plan to potentially start withdrawing its stimulus.
"The case for delaying any exit from stimulus has been enhanced by recent market moves," said Art Hogan, chief market strategist at National Securities in New York.
"The yield on the 10-year Treasury note has fallen since the Fed last met in mid-June, along with market measures of inflation expectations as the perceived threat of the Delta variant to worldwide growth has become the new investor narrative."
The June reading of the personal consumption expenditures price index - the Fed's main inflation measure - is due on Friday.
The Nasdaq Composite was up 0.64% by 12:05 p.m. ET, after posting its worst session in more than two months on Tuesday.
The Dow Jones Industrial Average was down 0.16%, shrugging off a 5.3% jump in Boeing Co following the company's first quarterly profit in almost two years.
The benchmark S&P 500 was up 0.07%.
Microsoft Corp edged 0.3% higher as a boom in cloud services helped it beat Wall Street expectations for revenue and earnings.
Facebook Inc, which competes with Google in web ad sales and is slated to report results late on Wednesday, rose 1.1%.
Focus will also be on after-market results from chipmaker Qualcomm Inc after Apple said on Tuesday chip shortages would start to bite into its mainstay iPhone business in the current quarter.
"We need to get more visibility into chip shortages," said Kim Forrest, chief investment officer at Bokeh Capital Partners in Pittsburgh.
"So many of the top companies have a component of technology, and even Google, while it did not talk about chip shortages, they're always rebuilding their data centers."
In other sectors, Starbucks Corp fell 2.8% after it lowered its fiscal 2021 forecast for China sales growth, while Pfizer Inc added 3.1% as it raised its outlook for full-year sales of its COVID-19 vaccine.
Advancing issues outnumbered decliners 1.53-to-1 on the NYSE and 2.07-to-1 on the Nasdaq.
The S&P index recorded 40 new 52-week highs and no new low, while the Nasdaq recorded 34 new highs and 53 new lows.
(Reporting by Sruthi Shankar, Sagarika Jaisinghani and Shashank Nayar in Bengaluru; editing by Uttaresh.V, Aditya Soni and Maju Samuel)