* To spend 17 billion euros in United States

* 2025 core profit beats poll

* Expects US capacity to grow to 22 gigawatts

* Shares indicated 1% lower on slight cut in 2027 outlook

(Adds chart, details on U.S. investments in paragraph 8)

By Christoph Steitz and Tom Käckenhoff

ESSEN, Germany, March 12 (Reuters) - Germany's largest

power producer, RWE, said on Thursday it would expand

more aggressively in the United States, a market where data

centres have significantly fuelled power demand, by investing in

new gas-fired power plants.

The move marks a major push by Germany's biggest utility

into a market where the rapid construction of data centres, as

well as the need to modernise ageing power infrastructure, has

fuelled a boom in generation assets and network equipment.

This is mainly driven by big tech firms, so-called

hyperscalers, which are planning to spend $600 billion this year

on artificial intelligence, a technology that needs substantial

power supply and has also benefited German industrial peers.

US IS RWE'S MOST IMPORTANT GROWTH MARKET

"The United States remains our most important growth market,

not least due to the rapidly growing demand for electricity,"

RWE said in its annual report, adding that more gas-fired power

plants would ensure round-the-clock supply.

"A decisive factor, particularly for industrial companies

and data centres."

Overall, the United States, where RWE already has 13

gigawatts (GW) of installed solar, wind and battery storage

capacity, will account for 17 billion euros ($20 billion), or

nearly half, of its planned spending by 2031.

Installed U.S. capacity is expected to increase to 22 GW as

a result, the company said, also releasing full-year results

that showed core profit fell 10% to 5.1 billion euros, still

beating the 4.9 billion poll.

RWE said it was developing a 5 GW pipeline of gas-fired

power plant projects in the United States, targeting Texas as

well as Midwestern states, adding that more than 3 GW would be

realised by 2035.

Shares in the company, which have risen nearly a fifth

year-to-date, were set to open 1.1% lower in pre-market trade,

with traders citing a slight cut in the group's outlook for 2027

core profit.

($1=0.8643 euros)