A group of preferred shareholders Friday evening refused to vote on an effort by Emmis Communications Corp. Chairman Jeff Smulyan to take the company private. It was the third such setback for Smulyan in two weeks.

Emmis called a shareholders meeting for Aug. 20 to take up the matter again as Smulyan, 63, negotiates with eight firms that banded together to prevent the sale. Collectively, the dissident group holds 38 percent of Emmis preferred shares.

That’s enough to prevent Smulyan from winning two-thirds approval from preferred shareholders to convert their shares into bonds—at 60 cents on the dollar—in exchange for the attractive interest rate of 12 percent.

Emmis shares closed at $2.05 Friday, one cent less than a week ago. The stock remained below Smulyan’s offer of $2.40 per share, indicating there is doubt that Emmis’ founder can pull off his plan. Smulyan’s offer through his JS Acquisition Inc. and New York private equity firm Alden Global Capital values the company at about $90 million.

Smulyan said after the first shareholders meeting held to vote on the matter Aug. 3 that he is considering an “alternative structure” for his bid to take the company private.

Smulyan’s proposal also requires approval from the holders of a majority of Emmis shares, a threshold Smulyan likely would be able to meet.

Founded by Smulyan in 1981, Emmis owns 23 radio stations in the United States and publishes regional magazines in seven cities, including Indianapolis Monthly. It also operates radio stations in Slovakia and Bulgaria.

The company’s audience base has been trimmed by competition from satellite radio and iPods at the same time advertisers have funneled more dollars to the increasing number of websites and cable television channels.

Over the past four years, Emmis’ revenue has swooned by 33 percent to $243 million. Its continuing operations have wracked up losses of more than $430 million.

That performance has caused Emmis’ share price to plunge since the last time Smulyan tried to take the company private in May 2006. At that time, Smulyan’s buyout group offered $15.25 per common share, but could not come to terms with the company’s board of directors.