* Indexes up: Dow 0.18%, S&P 500 0.25%, Nasdaq 0.40%

* US nonfarm payroll jump the most in 15 months in March

* March ISM non-manufacturing PMI slightly below

expectations

* Soleno Therapeutics ( SLNO ) jumps on Neurocrine's $2.9 bln

buyout deal

(Updates with late-morning trading)

By Purvi Agarwal and Avinash P

April 6 (Reuters) - Wall Street's main indexes kicked

off the week on a higher note on Monday after marking their

biggest weekly jump in four months in the previous session,

while investors assessed prospects of an end to the Middle East

conflict.

Iran conveyed its response to the U.S. proposal for ending

the war to Pakistan, rejecting a ceasefire and emphasizing the

necessity of a permanent end to the war, the official IRNA news

agency said, ahead of U.S. President Donald Trump's Tuesday

deadline to reopen the Strait of Hormuz.

Still, investors drew some comfort from a report that

indicated the U.S., Iran and a group of regional mediators are

discussing the terms for a potential 45-day ceasefire.

"The optimism is coming from talks about a ceasefire in

Iran. March was a tough month for stocks and investors really

just want to find a reason to be optimistic," said Melissa

Brown, managing director of investment decision research at

SimCorp.

"That's the driver of today's optimism but could turn into

tomorrow's concern quickly."

The S&P 500 financial index was the biggest boost,

up 0.7%, with JPMorgan Chase ( JPM ) and Visa in the lead.

These stocks also lifted the blue-chip Dow.

Tech stocks followed, with chip-linked firms among the top

gainers. Memory chipmaker Seagate ( STX ) rose 6.6% after Morgan

Stanley added it to its top-pick list. The Philadelphia SE

Semiconductor index was up 0.9%.

"The expectation is that tech earnings will continue to be

good ... if the stocks have been beaten down, maybe this is a

buying opportunity," said Brown.

Mining and healthcare stocks fell 0.6%

and 0.3%, respectively, capping gains.

At 11:50 a.m. ET, the Dow Jones Industrial Average

rose 83.20 points, or 0.18%, to 46,587.48, the S&P 500

gained 16.71 points, or 0.25%, to 6,599.40 and the Nasdaq

Composite gained 88.32 points, or 0.40%, to 21,967.50.

Trading volumes on Monday were expected to be thin as many

markets in Europe and Asia are closed for public holidays.

Wall Street's main indexes posted their first weekly gains

in six weeks on Thursday, as the prospects of an end to the

conflict soothed investor nerves.

Markets will scrutinize domestic inflation readings this

week to gauge if the conflict-driven spikes in energy prices

have trickled into the U.S. economy.

Friday's data showed U.S. job growth rebounded more than

expected in March, helping the Federal Reserve to focus on its

inflation mandate.

Money market participants are not pricing in any easing from

the central bank this year, compared to two cuts they had

expected before the war broke out, per CME Group's FedWatch

Tool.

On Monday, the Institute for Supply Management's

non-manufacturing purchasing managers' index for March came in

at 54, slightly below estimates of 54.9, according to economists

polled by Reuters.

Among others, Soleno Therapeutics ( SLNO ) shares surged

about 32% after Neurocrine Biosciences ( NBIX ) agreed to

acquire the rare-disease drugmaker for $2.9 billion in cash.

U.S.-listed shares of cryptocurrency-linked firms rose, with

Coinbase and Strategy up 2.8% and 5.7%,

respectively, as bitcoin prices edged higher.

Advancing issues outnumbered decliners by a 1.44-to-1 ratio

on the NYSE and by a 1.74-to-1 ratio on the Nasdaq.

The S&P 500 posted seven new 52-week highs and one new low,

while the Nasdaq Composite recorded 46 new highs and 50 new

lows.