Alliance Data Systems Corp. says its Epsilon unit will acquire DoubleClick's Abacus Unit for $435 million.

Abacus is a provider of data, data management and analytical services for the retail and catalog industry, as well as other sectors.

DoubleClick acquired Abacus in 1999 for $1.7 billion. The acquisition gave DoubleClick the ability to cross-reference its user information with Abacus' database of names and addresses to develop targeted online advertising, The Wall Street Journal reports.

"Today's announcement is representative of our ongoing commitment to offer a comprehensive suite of services that greatly enhance our clients' marketing efforts and their ability to improve their bottom line. It also provides prime cross-selling opportunities across Alliance Data's businesses," says Mike Parks, chairman and chief executive officer of Alliance Data.

The acquisition of Abacus is expected to close in the first quarter of 2007.

"Except for the online ad serving component, Alliance Data Systems ("ADS") seems to be transforming itself into DoubleClick – or at least DoubleClick as it used to be. Epsilon bought DoubleClick's email division back in April, and now has acquired Abacus, DoubleClick's data division. Abacus’cooperative databases contain lots of consumer transaction data-- many people buy from Abacus' cataloguers, which also have websites and retail stores. ADS will now have the ability to marry significant consumer financial data derived from its existing loyalty program and credit card customers with consumers' retail purchasing histories," says Elise Berkower,  EVP of privacy strategy, Chapell & Associates.