The Sun Record Co. logo, with its striking shades of vintage yellow and brown, is one of the most recognizable designs in popular music history. It's also a moneymaking trademark that the historic Sun Studio at 706 Union Ave. in Memphis may no longer be able to use if the Nashville-based owner of Sam Phillips' famous Sun Records has its way.

Sun Entertainment Corp. — started by Shelby Singleton Jr. after he purchased Sun's assets from Phillips in 1969 — filed suit in federal court in Nashville this week, contending that the separately owned Memphis studio is violating the terms of a 1991 licensing agreement that governs the use of the logo. The complaint says that the operators of the studio where Elvis Presley and Johnny Cash first recorded are improperly using "colorable imitations" of the logo in a way that avoids having to pay licensing royalties according to the terms of the 15-year-old contract.

John Schorr, president and general manager of Sun Studio Entertainment, the company that runs the Memphis studio, said he was "stunned" to learn about the lawsuit when made aware of it by The Tennessean on Wednesday.

"The ownership and management of Sun (Entertainment) has been to Sun Studio on many occasions spanning many years, without any indication of complaint about our licensed use of the Sun Record logo," Schorr said in an e-mailed response.

Mark Patterson, the Nashville attorney who filed the lawsuit on behalf of Sun Entertainment, said the company appears to be selling merchandise using unauthorized logos that are almost identical to the trademarked Sun design. In addition, Patterson said the studio's Web site streams music by Sun artists, potentially im plying a false connection to master recordings owned by Sun Entertainment company.

"We felt that some of the things they we're doing went beyond the scope of the licensing agreement," Patterson said of the studio operators. "They pushed the envelope too far."

The studio itself was originally started by Phillips in 1949 as the Memphis Recording Service ("We Record Anything-Anywhere-Anytime"). The space mostly sat empty from the late 1950s until 1987, when a Memphis musician and radio host named Gary Hardy opened the Sun Studio as a tourist attraction, prompting a lawsuit that resulted in the 1991 licensing agreement with Sun Entertainment. Hardy filed for bankruptcy in 1995.

Neither Patterson nor Singleton could say how much money might be at stake with this suit, though the Sun name has gained exposure in recent years with renewed efforts to market Elvis memorabilia and last year's high-profile Johnny Cash biopic, "Walk the Line."

"I really couldn't tell you how much money is at stake," Patterson said. "That's part of the reason we filed this, so we could find out. " (News, Source: The Tennessean)