* Futures up: Dow 0.57%, S&P 500 0.30%, Nasdaq 0.37%

* Apple ( AAPL ) names hardware veteran Ternus as new CEO to

succeed Cook

* Amazon ( AMZN ) climbs after pledging to invest up to $25 bln in

Anthropic

* UnitedHealth ( UNH ) gains after raising FY profit outlook

(Updates prices)

By Niket Nishant and Avinash P

April 21 (Reuters) - U.S. stock index futures rose on

Tuesday as renewed artificial intelligence optimism and strong

corporate earnings bolstered markets battered by a great deal of

back-and-forth over the resolution of the Middle East conflict.

J.P. Morgan raised its year-end target for the S&P 500,

citing AI and tech-driven earnings, while Amazon ( AMZN ) said

on Monday it will invest up to $25 billion in Anthropic,

signaling Big Tech is still willing to pour money into AI.

Amazon ( AMZN ) shares rose 2.7%.

Investors are also awaiting the Senate confirmation hearing

for Kevin Warsh, U.S. President Donald Trump's nominee to lead

the Federal Reserve.

Republican Senator Thom Tillis has promised to block the

confirmation until the Department of Justice ends an

investigation into Fed Chair Jerome Powell that Tillis sees as a

threat to the central bank's independence.

The outcome of the hearing could have far-reaching

implications for monetary policy. Typically, if a nominee for

Fed chair is not confirmed, the incumbent remains in place in

the interim. But Trump has vowed to fire Powell if he does not

leave when his term ends in May.

At 06:30 a.m. ET, Dow E-minis were up 282 points, or

0.57%, S&P 500 E-minis were up 21.75 points, or 0.3% and

Nasdaq 100 E-minis were up 98 points, or 0.37%.

Despite the uncertainty, AI hopes and upbeat earnings

prevented investors from retreating to the sidelines.

"The U.S. equity market should continue to make new highs in

(the) coming months on the back of continued earnings growth,"

analysts at Goldman Sachs said.

"Consensus earnings estimates have risen consistently in

recent weeks, providing the fundamental underpinning for the

market rally."

Of the 48 companies in the benchmark S&P 500 index

that reported earnings as of last Friday, 87.5% surpassed

analysts' estimates, compared with a long-term average of 67.4%,

according to LSEG data.

Wall Street will also be assessing a deluge of earnings on

Tuesday.

UnitedHealth ( UNH ) jumped 5.7% in premarket trading after

the healthcare conglomerate raised its annual profit forecast

and beat Wall Street expectations for the first quarter.

Peers CVS Health ( CVS ) and Humana rose more than

3.5% each.

GE Aerospace added 2.1% after reporting first-quarter

results.

WAR FUELS VOLATILITY

Markets have been pulled in opposite directions by a torrent

of conflicting headlines in recent days.

On Friday, Tehran's vow to reopen the Strait of Hormuz -- a

crucial waterway for oil shipping -- briefly sparked hopes for

de-escalation, which quickly faded over the weekend when Iran

fired what appeared to be warning shots at vessels and the U.S.

military seized an Iranian cargo ship.

Iran has said it would skip a second round of negotiations

with Washington, though a senior official later told Reuters the

country may yet send delegates to talks, expected to be held in

Islamabad.

Uncertainty around the end of the two-week ceasefire also

loomed.

"In the near term, equity market gyrations will likely

continue to mirror geopolitical volatility," Goldman analysts

said.

Alaska Air ( ALK ) fell 2.3% as the airline withdrew its

full-year profit forecast.

Apple ( AAPL ) was among the other stocks under the

spotlight in the premarket session, falling 0.3% after the

company said CEO Tim Cook would hand over the reins to longtime

hardware boss John Ternus.

Markets will be on the lookout for the retail sales reading

for March, due at 8:30 a.m. ET, to understand how the economy

has held up.

(Reporting by Niket Nishant and Avinash P in Bengaluru; Editing

by Devika Syamnath and Shinjini Ganguli)