By Arathy Somasekhar and Ron Bousso

HOUSTON, April 29 (Reuters) - Financial details of

Shell's vast oil and gas trading business are some of

the company's closest-held secrets. Documents in a lawsuit filed

by a former employee, however, revealed its U.S. crude trading

regularly earns around $1 billion every year.

Testimony by a former head of Shell's U.S. crude trading

division filed in a Texas state court has offered a rare look at

the huge profits of its trading operations and the multi-million

dollar bonuses bestowed on traders.

John Dimech, who was a manager in Shell's crude oil trading

group in Houston for 11 years, said in a deposition last year

that the crude trading unit typically made between $950 million

to $1 billion a year.

That is between 13% and 15% of Shell's overall U.S. pre-tax

profits in recent years, according to calculations based on

company filings.

Shell's 2022 tax contribution report detailed a pre-tax

profit of just over $7 billion total in the U.S. that year,

while its 2021 pretax profit stood at about $6.36 billion.

A Shell spokesperson declined to comment.

The British oil major does not disclose the financial

performance of its oil and gas trading desk, the world's

largest, although the lack of information worries some

investors. The business can generate bumper profits, but can be

volatile and even post losses.

Traders make money by buying and selling oil and gas using

gaps in supply and demand around the world to lock in profits.

Their pay often includes promises of large bonuses based on

their performance, that can be more than CEO Wael Sawan's annual

bonus, which was 2.7 million pounds ($3.4 million) last year,

according to the latest annual report.

In the Houston court filing, Shell denied a breach of

contract claim by former trading manager Eva-Maria Frohn, who

sought $15 million, including $6 million for 2021's bonus. She

received a more than $5 million bonus in 2020 for her work the

previous year.

Frohn claimed that a job transfer she was offered would not

be as lucrative as the job she held, making her redundant, while

Shell maintained that her job rejection amounted to a

resignation.

A jury last Tuesday rendered a verdict favorable to Shell,

nullifying Frohn's entire claim against Shell, according to the

law firm that represented the company.

Frohn's attorney did not reply to a request for comment.

($1 = 0.8005 pounds)