Clear Channel Communications Inc. (CCU), the largest U.S. radio station chain, on Tuesday posted slightly lower earnings, reflecting its strategy to cut advertising time on radio stations to attract listeners as well as the overall weaker ad market.

The company also bolstered its share buyback plan by $692 million.

The San Antonio, Texas-company reported second-quarter earnings fell to $220.7 million, or 40 cents a share, from $253.8 million, or 41 cents a share, a year earlier.

Revenue fell 1 percent to $2.46 billion from $2.49 billion.

The average Wall Street profit estimate was 40.5 cents a share, on revenue of $2.48 billion, as compiled by Reuters Estimates.

Revenue from radio broadcasting fell 6.5 percent, while billboard and other outdoor advertising rose 7 percent. The company's live entertainment promotion business, which the company plans to spin off, fell 1 percent.

The company approved a $1 billion share repurchase plan in February and has since bought back $692 million in shares. The authorization announced on Tuesday brings the amount earmarked for repurchases back to $1 billion over the course of the next year.