By Maha El Dahan and Michael Georgy

DUBAI, May 30 (Reuters) - At an industry event in Riyadh

two years ago, the Saudi energy minister paused at about 9 p.m.

in front of some 1,000 people and told them it was bedtime for

Amin Nasser, the chief executive of giant state-owned oil

producer Saudi Aramco.

He was not joking.

Over a career of four decades, Nasser has earned a

reputation for a style of dedication that means he will be

making sure he's ready for the challenges of the day ahead, not

mingling into the early hours.

"It was kind of embarrassing you know with protocol and all

these things, but it goes to show his work ethic and all that he

tends to do to stand out," said an industry source, speaking on

condition of anonymity.

Nasser has been patiently preparing for years for the order

to sell more shares in Aramco, after managing the company's

initial public offering in a record $29.4 billion listing in

2019.

The landmark deal is a major part of Crown Prince Mohammed

bin Salman's drive to diversify the economy away from oil. The

Saudi oil giant is one of the world's most valuable companies.

While juggling the daily management tasks of a company with

over 73,000 employees, Nasser has also addressed the questions

that surround how to meet the world's energy needs and become

increasingly outspoken on the issue.

HOMEGROWN TECHNOCRAT

Under Nasser, Aramco has invested in refineries and

petrochemical projects in China and elsewhere, expanded its

retail and trading businesses, and sharpened its focus on gas,

making its first foray into liquefied natural gas abroad last

year.

Before becoming CEO in 2015, The homegrown technocrat was an

unknown quantity in the West. In contrast to other Aramco CEOs,

he is not a product of a major U.S. university and instead

climbed the company's ranks after receiving a Saudi education.

Nasser began his career as a petroleum engineer. Before

becoming CEO, he held positions including vice president of

upstream when he led the company's largest capital investment

programme in its integrated oil and gas portfolio.

To steer the company smoothly, he has to retain the support

of two of the most powerful figures in the kingdom: Energy

Minister Prince Abdulaziz bin Salman and Yasir al-Rumayyan,

governor of Saudi sovereign wealth fund PIF who is also chairman

of Aramco's board of directors.

Nasser has become highly popular at Aramco by promoting a

decentralised culture and spending time with both leaders and

workers, analysts say.

During the Muslim fasting month of Ramadan, he makes a point

of visiting an Aramco field or plant every evening and breaking

the fast with crews.

Pleasing the elite is also part of his job. That means

keeping the petrodollars flowing, including for the ambitious

economic diversification plan of Crown Prince MbS, as he is

commonly known, that includes a massive urban and industrial

development project nearly the size of Belgium to be built along

the Red Sea coast, NEOM.

"Nasser's job is way bigger than that of the typical oil

company CEO. His job is not just producing and marketing oil,

but also keeping the Saudi government supplied with the revenues

necessary to remain afloat," said Jim Krane, energy research

fellow at Rice University's Baker Institute and author of the

book Energy Kingdoms.

"The security of the Saudi royal family depends to a large

extent on his success."

One of Nasser's biggest tests came in 2019 when drones and

missiles struck Aramco's Abqaiq and Khurais oil plants and

halved Saudi Arabia's crude output.

The United States and Saudi Arabia blamed Iran for the

attack. Tehran denied any involvement.

Nasser was at the Aramco emergency unit within seven

minutes, said the industry source. He did not micro-manage and

gave managers in the field the freedom to make decisions during

a high-pressure moment.

"Despite 50% of Aramco's operations being impacted by the

attack, within a matter of a few weeks, Aramco was able to

restore the bulk of its operations," said Mazen Alsudairi, head

of research at Al Rajhi Capital.

"This was possible because he continued the strong risk

management policy of the company that leaves no scope for

leniency."

(Editing by William Maclean)