Shares of Western Union fell after the company cut its outlook and reported declining revenue, citing acquisition delays and a lack of improvement in its Americas Retail business.

Shares were down 15% to $6.51 in Friday afternoon trading. The stock has fallen 31% so far this year.

"In the second quarter, we did not see the improvement in Americas Retail that we had expected, and the delayed close of our Intermex acquisition pushed out expected synergies, contributing to meaningful margin pressure and lower-than-expected EPS," Chief Executive Officer Devin McGranahan said.

The results mean that Western Union will need to further accelerate its cost cuts in the second half of the year, McGranahan said.

Western Union also cut its outlook, forecasting full-year adjusted earnings of between $1.25 and $1.35 a share on revenue growth between 3% and 5%.

Western Union had previously guided for adjusted earnings of between $1.75 and $1.85 a share on 5% to 8% revenue growth. In late June, prior to the second-quarter release, analysts polled by FactSet were expecting adjusted earnings of $1.75 a share on $4.28 billion in revenue, representing 5.6% growth.

In the second quarter, the company reported a profit of $76.7 million, or 24 cents a share, compared with $122.1 million, or 37 cents a share, a year earlier.

Adjusted earnings were 31 cents a share. Analysts were targeting 42 cents a share.

Revenue fell 1% to $1.01 billion, beneath analyst expectations for $1.02 billion.