* Futures off: Dow 0.27%, S&P 500 0.30%, Nasdaq 0.40%

* Trump mulls Kharg Island takeover, report says

* S&P 500, Dow on track for fourth-straight weekly loss

* FedEx ( FDX ) up on strong forecast; Amazon ( AMZN ) plans smartphone

comeback

(Updates to before market open)

By Johann M Cherian and Utkarsh Hathi

March 20 (Reuters) - Wall Street's main indexes were set

to open lower on Friday as the Iran war approached its fourth

week, roiling energy markets and prompting investors to

aggressively reprice bets on the Federal Reserve's interest-rate

cuts.

The conflict in the Middle East showed no signs of easing as

Iran attacked an oil refinery in Kuwait and a report said that

the Trump administration is planning to occupy or blockade

Iran's Kharg Island to pressure Iran to reopen the Strait of

Hormuz.

Investors also weighed major nations' efforts to ease energy

supplies, as Brent prices slipped 1% to $107 a barrel.

Offering some comfort, FedEx ( FDX ), often seen as a

barometer of business activity, issued upbeat forecastsand said

global demand was holding steady despite geopolitical tensions,

sending its shares up 6.7% in premarket trading. Rival United

Parcel Service ( UPS ) added 0.8%.

A flurry of central bank decisions this week along with the

Fed acknowledged how the conflict had complicated policymaking.

Fed Governor Christopher Waller said that if oil prices stay

elevated for months it would start bleeding into core inflation.

While U.S. policymakers are still penciling in at least one

quarter-point interest rate cut this year, markets are less

convinced. Traders have pushed their bets for a rate cut to

sometime in 2027, from December 2026 earlier this month,

according to LSEG-compiled data.

"Central banks adopting a wait-and-see stance is the logical

thing to do," said Michael Brown, senior research strategist at

Pepperstone.

"However, raising the prospect of tightening policy, to

counter what appears a low risk of inflation proving more

prolonged, raises the likelihood that a policy mistake will be

made."

At 8:57 a.m. ET, Dow E-minis were down 127 points,

or 0.27%, and S&P 500 E-minis were down 19.75 points, or

0.30%. Nasdaq 100 E-minis were down 100.75 points, or

0.41%.

The CBOE volatility index, sometimes referred to as

Wall Street's fear gauge, edged up 0.69 points to 24.75. Futures

tracking the rate-sensitive Russell 2000 index slipped

0.40%.

Friday also marks the once-in-a-quarter simultaneous expiry

of derivatives contracts tied to stocks, index options and

futures, also known as "triple witching," which can boost

trading volume and aggravate volatility.

Wall Street's benchmark S&P 500 and the blue-chip Dow

were on track to finish their fourth-straight week in the

red, although a modest bounce-back in AI stocks such as Advanced

Micro Devices ( AMD ) and Micron have cushioned the fall

on the Nasdaq.

All the three indexes also slipped below their 200-day

moving average, a technical indicator reflecting long-term

momentum, while the small-cap-focused Russell 2000 index

briefly logged a 10% drop from all-time highs earlier this week.

Super Micro Computer ( SMCI ) tumbled 24.6% after three

people associated with the artificial intelligence server maker

were charged with helping smuggle at least $2.5 billion of U.S.

AI technology to China in violation of export laws.

Gains have been strong in energy stocks. The S&P 500 sector

index is set for its longest weekly winning streak on

record with a thirteenth-straight week of gains as geopolitical

events in Venezuela and the Middle East dominated much of the

first quarter.

Halliburton ( HAL ) was up marginally and Cheniere Energy

added 2.1% on Friday.

Amazon ( AMZN ) slipped 0.4%. Reuters reported that the

megacap introduced its first smartphone, hoping to take on Apple

and Samsung.