Dec. 4 (Bloomberg) — New York Times Co.’s namesake newspaper will probably fall short of the 100 newsroom buyouts it is seeking and will have to fire employees to cut costs, Executive Editor Bill Keller said.

“If that is indeed the case, as we expect, we will be forced to resort to some number of layoffs,” Keller said today in a memo to newsroom staff. Diane McNulty, a company spokeswoman, confirmed the memo in an interview.

Keller said in October that the newspaper would eliminate 100 newsroom jobs, either through voluntary buyouts or firing, and make undisclosed budget cuts in the newsroom and business operations. Times Co. has pared sections, jobs and pay to cope with declining advertising revenue.

Times Co. reported a 30 percent drop in ad sales in the first nine months of this year to $550.7 million in the division that includes the New York Times and International Herald Tribune newspapers.

McNulty declined to comment beyond the staff letter.

Times Co., based in New York, rose 17 cents, or 2 percent, to $8.72 at 4 p.m. in New York Stock Exchange composite trading. The shares have gained 19 percent this year.