Lee Enterpeises

Warren Buffett's Berkshire Hathaway held over 1.6 million shares of Lee Enterprises, about 3.2 percent of its outstanding shares, as of March 31, according to a filing with the SEC late today. On that date the stake was worth $2.1 million. The total market value of the company is around $60 million.

The stock is soaring in after-hours trading, up $0.29 to $1.44 as of 4:40p ET. That's an increase of more than 25 percent.

The Lee stake is tiny by Berkshire standards, but its particularly interesting because Buffett's company had wanted to keep it secret.

In its May 15 filing listing its U.S. stock portfolio as of the end of the first quarter, Berkshire had said some information was being kept confidential.

Usually, the SEC grants Berkshire's requests for secrecy, but this time it didn't.

Tonight's filing says the request for "confidential treatment" was denied on May 25.

It's a continuation of Buffett's local newspaper play. Lee owns 49 daily newspapers and 300 weekly newspapers. Most of them are in midsize markets, but it also publishes the St. Louis Post-Dispatch.

In November, Berkshire bought Buffett's home-town newspaper, the Omaha World-Herald.

More recently, Berkshire bought 63 newspaper from Media General for $142 million.

Buffett has said that the newspaper business overall is in trouble, but he's optimistic about small to mid-sized newspapers that provide local news and information available nowhere else.

In a letter to all of Berkshire's newspapers less than two months ago, Buffett wrote that he's looking for more papers to buy. "We will favor towns and cities with a strong sense of community, comparable to the 26 in which we will soon operate. If a citizenry cares little about its community, it will eventually care little about its newspaper... It's your job to make your paper indispensable to anyone who cares about what is going on in your city or town."