TOKYO/NEW YORK (Reuters) - U.S. investment bank Merrill Lynch & Co MER.N will announce $6 billion to $8 billion of asset write-downs in its first quarter results on Thursday, the Wall Street Journal reported on Wednesday, citing a person familiar with the matter.

The latest write-downs would increase total debt losses since October to more than $30 billion, the paper said. The setbacks will contribute to a third straight quarterly net loss at Merrill, the longest losing streak in its 94-year history.

Merrill Lynch spokeswoman Jessica Oppenheim declined to comment.

Investors have been bracing for more bad news from big U.S. banks reporting their first-quarter results this week as the housing market collapse and credit market turmoil has taken a big toll on their balance sheets.

On average, analysts who cover Merrill have told clients they expect $6 billion to $8 billion of write-downs.

"In this environment, anything is plausible," Sandler O'Neill + Partners analyst Jeff Harte said.

The real key to Merrill's actual results will be what steps the firm has taken to reduce its exposure to risky assets going forward.

"It's how much is written down. If the losses are bigger and it's because they reduced exposure, that may not be so bad," Harte said. "The actual earnings number is less relevant than the health of underlying business."

The Wall Street Journal also reported that Merrill is preparing to slash 10 to 15 percent of jobs in some struggling business areas, such as bond financing.