Shares in Computer Sciences Corp. jumped about 10 percent Monday even though cold water was tossed on a long-running rumor that the company would go private.

Shares in the El Segundo-based IT services provider have gained nearly 30 percent over the last year mainly fueled by rumors that the company was going to be taken private by a large private equity player. However, Jefferies & Co. analyst Joseph Vafi said late Friday that that scenario was now extremely unlikely.

“My sense is that a private equity takeout would have been unlikely then, and now, in a tightening liquidity market, there’s a zero chance of a sale happening,” he said in a research report.

CSC has outperformed the Standard & Poor’s 500 Index which has gained 19 percent between August 2006 and the end of July 2007, the same period Computer Sciences gained more than 29 percent.

Shares in CSC jumped $5.20, or 9.9 percent, to $57.99 in trading Monday on the New York Stock Exchange.