The companies whose shares are moving in pre-market trade on Wednesday are: Western Digital, AK Steel Holding, Salesforce.com, United States Steel, Micron Technology, CA, Boeing, Xerox and Yahoo.

Western Digital Corp. (NYSE:WDC) shares advanced 3.19 percent to $33.33 in pre-market trading session.

AK Steel Holding Corp. (NYSE:AKS) shares gained 2.76 percent to $16.00 in pre-market trading session. The company reported narrower-than-expected fourth quarter loss of $0.49 per share against analyst estimation of $0.64 per share.

Salesforce.com (NYSE:CRM) shares advanced 1.94 percent to $126.38 in pre-market trading session.

United States Steel Corp. (NYSE:X) shares gained 1.59 percent to $58.21 in pre-market trading session. The company reported overall losses for the fourth quarter of 2010, but the losses were smaller than those experienced in fourth-quarter and full-year 2009.

Micron Technology Inc. (NASDAQ:MU) shares gained 1.45 percent to $10.12 in pre-market trading session. The company has been conferred the Distinguished Partner in Progress (DPIP) Award for its significant contributions to the growth of the semiconductor industry in Singapore.

CA, Inc. (NASDAQ:CA) shares declined 3.79 percent to $24.40 in pre-market trading session. The company said its license and maintenance renewals will decline 10 percent in 2011 as it continued to witness a slowdown in product sales at its high-margin mainframe business.

Boeing Co. (NYSE:BA) shares declined 2.89 percent to $70.15 in pre-market trading session. Its fourth quarter earnings declined 8 percent to $1.16 billion or $1.56 per share, from $1.27 billion or $1.75 per share in the same period last year. It expects 2011 earnings in the range of $3.80 to $4 per share against analysts’ estimation of $4.54 per share.

Xerox Corp. (NYSE:XRX) shares declined 2.37 percent to $11.13 in pre-market trading session after the company said its fourth-quarter net income declined 5 percent to $171 million or $0.12 per share, from $180 million or $0.20 per share in the same quartet last year.

Yahoo! Inc. (NASDAQ:YHOO) shares declined 2 percent to $15.70 in pre-market trading session. The company’s net income rose to $312 million or $0.24 per share, from $153 million or $11 per share in the same quarter last year. But revenue fell 4 percent to $1.21 billion and said it will cut 1 percent of its staff.

Nyse New york city New York NYSE Euronext