Oracle Corp. agreed to buy Sun Microsystems Inc. for about $7.4 billion in cash, stepping in afte International Business Machines Corp.’s talks to purchase the server maker collapsed. 

The acquisition probably will add $1.5 billion to Oracle’s operating profit, excluding some items, in the first year.The purchase will give Oracle Sun’s Java programming language and Solaris operating system software, which works with its database programs. The takeover also marks the company’s entry into the server-computer market, allowing it to challenge IBM in that business and sell more products for corporate data rooms that run networks and Web sites.

IBM was in takeover discussions with Sun in the past month, with negotiations breaking down over price, according to people familiar with the situation.