April 2 (Bloomberg) -- International Business Machines Corp. is planning to announce its purchase of Sun Microsystems Inc. on April 6, a person familiar with the matter said.

IBM intends to pay between $9 and $10 a share for Sun, said the person, who declined to be named as the talks are still under way. At those prices, it would be the largest acquisition in IBM’s history.

The purchase would give IBM almost half of global server- computer sales and Sun’s software portfolio, including the Solaris operating system. A deal could spark more consolidation in the industry, said Shaw Wu, an analyst at Kaufman Bros.

“It’s almost like a chess game -- what’s your move,” said San Francisco-based Wu, who doesn’t own shares of IBM or Sun. “One company makes their move, then you make your move.”

IBM spokesman Ed Barbini declined to comment. Sun spokesman Shawn Dainas didn’t immediately return a call seeking comment.

Sun shares, which jumped 79 percent on March 18, the day the deal was first reported, have since fallen 7.6 percent on speculation a deal would fall through.

Sun, based in Santa Clara, California, rose as much as 24 cents to $8.45 in extended trading, after gaining 21 cents to $8.21 today on the Nasdaq Stock Market. IBM climbed $3.21 to $100.82 today in New York Stock Exchange composite trading.

Sun makes about half its total sales from servers, which run corporate networks and Web sites. It counts AT&T Inc. and China Mobile Ltd. among its customers.

Sales of servers fell 14 percent industrywide in the fourth quarter as businesses reined in spending in the recession, according to researcher IDC in Framingham, Massachusetts.

IBM Chief Executive Officer Sam Palmisano, who took the helm in 2002, said last month he planned “to go on offense” during the recession and make acquisitions.

To contact the reporter on this story: Katie Hoffmann in New York at khoffmann4@bloomberg.net; Connie Guglielmo in San Francisco at cguglielmo1@bloomberg.net

Last Updated: April 2, 2009 20:24 EDT