Sun Microsystems Inc. announced plans on Wednesday to buy MySQL, an open-source database software company for a proposed $1 billion.

The deal will make the Santa-Clara based company one of the first major public companies to offer open-source software, putting itin line with the three big vendors in the $15 billion database market: IBM, SAP, and its former database partner, Oracle.

Sun said in a statement it will pay $800 million in cash and assume $200 million in options to acquire MySQL. The Swedish company makes open-source database software used by companies such as online search leader Google Inc., popular social-networking site Facebook Inc., Chinese search engine Baidu and Finnish phone maker Nokia Corp.

The deal will help spread MySQL's software to large corporations, which have been the biggest customers of Sun's servers and software. Sun will boost MySQL's distribution through relationships with other server makers such as IBM Corp. and Dell Inc, the company said.

MySQL is the rapidly growing market leader in open-source database software, particularly among Web-based companies, where it commands about 80 percent of the global market, according to Sun Chief Executive Jonathan Schwartz.

In a separate statement, the company said its second quarter revenue would narrowly exceed Wall Street estimates. Profit will be in the high end of analysts' expectations. Sun expects net income of between $230 million to $265 million, or 28 cents to 32 cents per share. Analysts surveyed by Thomson Financial were expecting profit of between 22 cents and 38 cents.

Sun predicts $3.6 billion in sales during the second quarter. Analysts were expecting, on average, $3.58 billion in sales. The company was expected to release its results January 24.