Cox Enterprises has announced that it is putting most of its newspapers on the block, as well as Valpak, its direct mail giant. Newspapers, TV and radio currently now make up just 20 percent of the company’s revenues as it has diversified with cable TV and holdings such as AutoTrader and Manheim auto auctions, and the Adify ad network, which it purchased in April for $300 million. In 2007, the company had earnings of $15 billion and employed 83,000 people.

Three of Cox’s largest newspapers are being kept in-house. These include The Atlanta Journal Constitution, The Palm Beach Post and The Dayton Daily News (where Governor Cox began his media odyssey in 1898). The newspapers that will be sold include the Austin American-Statesman and a number of smaller titles in Texas, North Carolina and Colorado. The Statesman has a circulation of 150,000 and has been at the vanguard of online experimentation and community blogging with its austin360.com.

Valpak’s inclusion is something of a surprise. The “blue envelope company,” which was acquired by Cox in 1991, recently invested in a state-of-the-art production facility that enables highly addressable targeting.

According to the release, Cox intends to use the proceeds from the sales to improve the competitive position of existing properties and develop new ones using the latest technologies. “Recent examples include an investment to develop next-generation wireless and mobility services for Cox Communications Inc. and investments in technology, global expansion and innovative products at Manheim, which is transforming the wholesale vehicle buying and selling experience,” it said. Presumably, Cox’s Kudzu directory and local ratings service is also part of this next generation of services.