DETROIT, Oct 1 (Reuters) - European automakers are most

likely affected by the dockworkers strike at U.S. East Coast and

Gulf Coast ports because they rely heavily on those locations,

but a longer walkout could hit the industry more broadly if

suppliers suffer, analysts said.

The dockworkers began their first large-scale stoppage in

nearly 50 years early on Tuesday, halting the flow of about half

the nation's ocean shipping.

The International Longshoremen's Association union

representing 45,000 port workers had been negotiating with the

United States Maritime Alliance (USMX) employer group for a new

six-year contract.

"The East Coast brings in a lot of cars, especially the port

of Baltimore," said Steve Hughes, CEO of HCS International,

which advises the auto sector on shipping issues. "If (the

strike) turns into weeks, it's going to be a tragedy."

In the last 12 months, the ports on strike handled $37.8

billion worth of vehicle imports, Hughes said. And that doesn't

include auto parts, which are used in both making vehicles and

the replacement parts market, he said.

"If you look at a GM car, you're going to find all sorts of

European and Asian parts in those cars now," Hughes said.

The Motor & Equipment Manufacturers Association, a trade

group for auto suppliers, called on President Joe Biden and his

administration to force both sides back to the bargaining table.

A shortage of parts could lead some automakers to reduce

vehicle production, although analysts said some may quietly

welcome that. Stellantis ( STLA ), for example, has very high

vehicle inventories.

Barclays analyst Dan Levy said 70% of auto parts imports

into the U.S. come via the affected ports, although companies

likely built up some inventory since the strike risk had been

visible for a while. If automakers are forced to fly in parts,

that could drive up costs.

"All of this is very, very inflationary," Hughes said.

European automakers, many of which use the ports on strike,

would be the most affected, Levy said in a research note.

"The European (automakers) lean heavily on Baltimore for

imports and Southeastern ports (i.e. Charleston) for exports, as

most of their U.S. production exposure is in this region," he

said.

BMW said it was monitoring the situation closely

and working to minimize any impact, while Volvo Cars

said it was devising contingency plans but had not

yet experienced any noticeable impact. Officials with

Volkswagen and Mercedes could not

immediately be reached to comment.

European imports have accounted for as much as half of the

German automakers' U.S. sales in recent years and Volvo Car is

even more reliant, Levy said. However, with inventories higher

than usual, the companies may have prepared and the strike

impact could be limited barring a long walkout, he said.

Truckmaker Volvo said the company stockpiled

parts and looked into rerouting shipments to minimize impact and

doesn't expect any impact in the short term.

Detroit automakers could actually benefit modestly as

reduced industry inventories could limit pricing pressure, Levy

said. The companies, including General Motors ( GM ) and Ford

, are more likely affected by the import of parts since

most of their vehicle imports come by truck and rail from Canada

and Mexico, he said.

"We are carefully monitoring the situation and have

contingency plans in place," GM said in a statement. "We will

continue to work to mitigate any significant impact to our

operations and will make adjustments as needed."

The Detroit automaker declined to provide details on how it

uses the ports or the nature of its contingency plans.

Ford said it was monitoring the situation, but said it was

too early to speculate on potential impacts.

Asian automakers may be less affected, Levy said.

Toyota ( TM ) built up extra vehicle inventory over the

last couple of weeks to help buy it time and it was watching the

talks closely, Toyota North America Executive Vice President

Jack Hollis said in an interview.

Mazda ( MZDAF ) said the ports of Baltimore and Jacksonville,

Florida, were important for the Japanese automaker, but its

vehicle inventories were sufficient to meet short-term demand.

Honda ( HMC ) said it was affected by the strike, without

providing details.

Hyundai said its logistics affiliate, Hyundai

Glovis, was closely monitoring the talks and working on

alternate plans to ensure delivery of vehicles.