IBM is to buy data integration software maker Ascential Software for about US$1.1 billion in cash. Ascential's products are used to build data warehouses, feed data into business intelligence systems, and consolidate enterprise applications, among other things.

The acquisition is subject to approval from Ascential's shareholders and regulators, as well as other customary closing conditions. IBM expects to complete the purchase in the second quarter of 2005.

After the acquisition, Ascential will become a business unit within IBM's Information Management software division. Ascential's products will become part of IBM's software offerings and sold through IBM's and Ascential's sales channels and partners.

Data integration is a key part of IBM's software strategy. The Ascential Enterprise Integration Suite complements IBM's WebSphere Information Integrator products, according to IBM. Ascential has more than 3,000 customers worldwide. IBM and Ascential already have more than 550 joint customers, the companies said.

Ascential (ASCL) is publicly held. IBM has agreed to buy the company for $18.50 cash per share, a premium of 17.8 percent over Ascential's Friday closing price of $15.70 on the Nasdaq stock exchange.