Shares of Colombian state-controlled telephone company Empresa de Telecomunicaciones de Bogota SA (ETB.BO) fell 3.7% Tuesday morning after the company announced yet another delay of the sale of a controlling stake.

ETB delayed the sale of a controlling stake to a private operator to July 26 from June 30. The company originally planned to hold the auction on Oct. 16, 2009.

"Every time they announce a delay, shares fall a little," said Melissa Mantilla, a market analyst with local brokerage Corredores Asociados.

Shares were down 3.7% to 1,045 Colombian pesos ($0.55) as of 1 p.m. EST.

Mantilla said the company is delaying the sale as it is still waiting for the Colombian anti-trust agency's opinion on the potential bidders.

ETB hasn't released the list of registered bidders, but Spain's Telefonica SA (TEF) and Mexico's Telefonos de Mexico SA (TMX) as well as Millicom International Cellular SA (MICC) were mentioned as possible bidders.

ETB, which is controlled by the Bogota city council, plans to sell new shares, equivalent to a 36.6% stake, to a new partner, which will be selected during a public auction on July 26. The winner will be the one that offers the highest price per share.

The city council, which controls the company, will change its current shares into non-voting shares.

The new partner will then commit to hold a tender offer to buy minority shareholders' stakes at the same price.

In the case that all minority shareholders decide to leave the company, the partner would end up with a stake close to 49%, but with a majority of voting shares.

The company also delayed the deadline for the tender offer to Jan 3, 2011.

-By Inti Landauro, Dow Jones Newswires; 57-1-694 00 76; colombia@dowjones.com