TOKYO, June 15 (Reuters) - Japan's Nikkei index headed for a fourth straight session of loss on Wednesday amid nerves ahead of a Federal Reserve policy decision later in the day that could see a much more hawkish shift and potentially put economic growth at risk.

The Nikkei share average dropped 0.73% to 26,435.01 as of the midday break, on course for its longest losing streak in more than three months.

Of the Nikkei's 225 components, 151 fell versus 69 winners, while five were flat. Energy was the worst-performing sector by far, sinking 3.42% following a retreat in crude oil prices. The only winners were financials — up 0.3% amid higher global bond yields — and real estate, which rose 1.03%.

The broader Topix slid 0.72%.

Money markets are now certain the Fed will raise rates by 75 basis points later in the day, which would be the biggest increase since 1984, after data at the end of last week showed U.S. consumer price inflation running red hot.

"While investors await the Fed's decision, the mood in the market is strongly wait-and-see," making active buying of shares difficult, said a market participant at a Japanese securities firm.

"At the same time, there is a sense in some parts of the market that recent declines have gone too far, and a break below 26,500 is likely to see dip buying emerge."

Chip-making equipment manufacturer Tokyo Electron was the Nikkei's biggest drag, shaving off 20 points with its 1.08% drop. Its peer Advantest sank 1.41%, despite gains for chip-related shares on Wall Street overnight.

Department store operator Isetan Mitsukoshi Holdings was the biggest percentage decliner, down 5.74%. That was followed by a 4.23% slide for oil company Inpex (Reporting by Tokyo markets team; editing by Uttaresh.V)