LONDON, April 3 (Reuters) - Norwegian car shipping firm Wallenius Wilhelmsen estimates a $5 million to $10 million hit to core earnings from last week's U.S. Baltimore bridge collapse and expects the key ship channel to be closed for weeks, it said on Wednesday.

The company said its vessel Carmen remained stuck in Baltimore's port with the ship and its crew ready to sail as soon as the shipping channel was reopened.

Recovery teams opened a second channel enabling smaller vessels to navigate the Port of Baltimore on Tuesday, but most commercial shipping remains blocked by the collapsed bridge and stranded container ship that brought the structure down a week ago.

"We have estimated that the aggregated provisional total financial impact on EBITDA of the situation is in the range of $5-10 million, assuming the disruptions last for up to a month," Wallenius Wilhelmsen, one of the world's leading vehicle carriers, said in a statement on Wednesday.

"We currently expect the closure to last for weeks and have based our impact estimates on that assumption," it said.

"Once open, we anticipate the terminal will also promptly resume normal cargo operations as vessels begin to make port calls as previously scheduled."

"There is of course risk of delays to the anticipated reopening, or unforeseen challenges in the salvage operations."

The Port of Baltimore ranks first in the U.S. for the volume it handles of autos and light trucks, farm and construction machinery, imported sugar and imported gypsum, according to the state of Maryland.

Some terminal operations outside the affected area have resumed. (Reporting by Jonathan Saul; Editing by Jan Harvey)