(Reuters) - A look at the day ahead in U.S. and global markets by Samuel Indyk

The wobbly start for markets in the second quarter could worsen on Wednesday. Federal Reserve Chair Jerome Powell is due to deliver a speech, and markets are doubting whether the central bank will proceed with easing policy as early as June.

Money market traders are at odds with the Fed - and most analysts - regarding the timing of the first interest rate cut and the scale of easing this year.

Markets are still not fully pricing a cut until July, although they are banking on a roughly-65% chance of a cut in June. Meanwhile, they've also lowered their expectations for three cuts in 2024, but with inflation sticky and economic data strong, the Fed might be slowly coming around to that view themselves.

"I think the bigger risk would be to begin reducing the funds rate too early," Federal Reserve Bank of Cleveland President Loretta Mester said on Tuesday, although she wouldn't rule out a June cut if upcoming inflation data met her forecasts for a further decline.

Powell, in reference to Friday's personal consumption expenditures data, said the inflation reading was "along the lines of what we would like to see".

His comments on Wednesday will be scrutinized for more clues on whether the June confab is the appropriate time to start loosening policy.

The debate over the timing of the first rate cut has kept Treasury yields elevated, posing a threat to the equity rally that has made U.S. stocks increasingly expensive while hitting record highs.

On Tuesday, the benchmark 10-year Treasury yield hit its highest level in four months, while the S&P 500 has slipped almost 1% to start the quarter.

Investors will also be watching for the impact on supply chains after the strongest quake in 25 years hit Taiwan, disrupting the semiconductor sector in particular.

"We believe this could lead to supply disruptions in the tech supply chain," Barclays analysts said in a note.

Taiwan Semiconductor, a major supplier to Apple and Nvidia, initially evacuated some fabrication plants, although later added that employees were returning to work. Its shares slipped 1.3% in Taipei.

Elsewhere, data releases on Wednesday include the ADP's report of private-sector payrolls, a precursor to Friday's official nonfarm payrolls readout, and the ISM services index for March.

Back to Wall Street and stock index futures are signalling another cautious start, with S&P and Nasdaq futures edging down.

The dollar remains elevated, with the yen near 152, close to its weakest level in decades and keeping traders on edge for intervention from Japanese officials.

Key developments that should provide more direction to U.S. markets later on Wednesday:

* Fed's Powell, Bowman, Goolsbee, Barr and Kugler due to speak

* ADP nonfarm private employment, ISM non-manufacturing

* U.S. Treasury to auction four-month bills