March 2 (Reuters) - Children's clothing company Carter's Inc forecast first-quarter earnings below market estimates saying rising raw material costs would eat into margins, sending its shares down 4 percent.

Carter.com

Carter's, which owns retail stores and also sells its merchandise through discounters like Wal-Mart Stores Inc and Target Corp , said higher product costs will continue to hurt gross margins throughout fiscal 2011.

"Since our most-recent call with you last October, cotton prices have increased by nearly 60 percent, far beyond what most had expected," Chief Executive Michael Casey said on a conference call with analysts.

The CEO said fall 2011 costs are expected to be up about 25 percent, and the company is going to raise prices to help fight that.

"We're not raising our prices 25 percent, however," he said, but did not say how much the prices would go up.

For the first quarter, the company expects to earn 45-50 cents a share, while analysts on average were expecting earnings of 61 cents, according to Thomson Reuters I/B/E/S.

For the latest fourth quarter, margins fell 200 basis points versus last year, but strong sales offset the damage.

Carter's wholesale sales rose 25.4 percent to $157.7 million, and on the mass-channel front, the company enjoyed additional shelf space at Walmart and strong demand at Target.

Carter's sells its Just One You brand at Target and Child of Mine brand at Walmart.

For the fourth quarter, Carter's earned $34.9 million, or 60 cents per share, compared with $33.0 million, or 56 cents per share, a year ago. Sales rose 17 percent to $495.3 million.

Analysts on average had expected earnings of 57 cents a share, on sales of $485 million.

Shares of the company were down 95 cents at $26.79 in morning trade on the New York Stock Exchange. They touched a low of $26.50 in early trade. (Reporting by Nivedita Bhattacharjee; Editing by Gopakumar Warrier)