LONDON, April 30 (Reuters) - Unable to predict the

impact of U.S. President Donald Trump's ever-changing trade war,

Stellantis ( STLA ) and Mercedes-Benz became the latest automakers on

Wednesday to yank their profit guidance citing market

uncertainty wrought by tariffs.

Volkswagen issued guidance at the bottom end of

its forecast, but UBS analyst Patrick Hummel wrote in a client

note that the German automaker's outlook did not "include any

impact of U.S. tariffs," calling it "essentially a withdrawal of

guidance".

Trump's trade war has pummeled markets in recent weeks and

even before the latest moves, a Reuters analysis showed that

about 40 companies worldwide have pulled or lowered their

forward guidance in the first two weeks of the first-quarter

earnings season, including General Motors ( GM ) and Volvo Cars

.

The moves underscore the chaos unleashed by the

ever-changing tariffs and the uncertainty in boardrooms and on

Main Street, which is stifling Americans' appetite for spending.

The 25% tariffs on imported autos imposed earlier this month

are expected to raise U.S. car prices by thousands of dollars,

reducing demand and piling pressure on an automobile industry

already struggling with a slowing transition to electric

vehicles.

Faced with a lack of clarity, Mercedes executives exuded an

aura of studied calm during the company's first-quarter

conference call with analysts, referring to the chaos of Trump's

opaque, shifting tariff policy as a "dynamic market

environment".

Chief Financial Officer Harald Wilhelm told analysts that

full-year guidance "cannot be provided today with a reliable

degree of certainty".

But he warned if U.S. tariffs remained in place all year, it

would shave 3 percentage points off profit margins for car sales

and 1 percentage point for vans.

CEO Ola Källenius said the premium German automaker was

still holding "constructive" talks with the Trump administration

on its future U.S. production footprint, but stressed that

Mercedes is determined to "see this through with a steady hand".

Investor reaction was muted, as markets digested the latest

orders issued by Trump on Tuesday which offered some tariff

relief to U.S. domestic automakers.

Under those orders, automakers will no longer also be

subject to 25% tariffs on steel and aluminum or on Canadian and

Mexican goods related to the U.S. fentanyl crisis. They would

also receive credit for U.S.-assembled vehicles.

Volkswagen and Mercedes shares were down 0.5% and 0.9%,

respectively, while Stellantis ( STLA ) - which is far more reliant on

U.S. production and stands to benefit more from the changes -

was up 1.8%.

READY TO WORK

Despite pleas from analysts on a quarterly earnings call,

Volkswagen CFO Arno Antlitz declined to quantify the impact of

tariffs, saying it was too early to do so.

"We stand ready to work with policymakers to find solutions

to support the industry while preserving opportunities for

workers," Antlitz said, adding the group would adjust its

forecast once there was more clarity.

The auto industry plans years ahead, weighing billions of

dollars in investments in assembly plants and new models based

on car sales forecasts. The bedrock of all those investments is

market certainty.

"Trump has a track record of changing course, so there's

every chance we'll see further adjustment," said Philipp Sayler

von Amende, chief commercial officer at British online car

marketplace Carwow.

"From investment decisions to stock availability and

consumer confidence, this is a global industry that needs

clarity - not surprises - to thrive."

Stellantis ( STLA ) said in a statement that its decision to pull

guidance was "due to evolving tariff policies, as well as the

difficulty (in) predicting possible impacts on market volumes".

Pal Skirta, analyst at German research firm Metzler, said

Trump's move on Tuesday to give automakers two years to boost

the percentage of local components in U.S.-made vehicles

indicated his administration was unlikely to pull back from

tariffs and would probably stick to pushing for an increase in

domestic production.

"This could result in two burdens for manufacturers," he

said, consisting of "ongoing tariff costs" while also having to

invest in restructuring global supply chains and increasing U.S.

production.