NEW YORK: TV adspend in the US declined -5% year-on-year in Q2 2015, according to a new industry study, which also noted that growth in the digital sector appears to be slowing down.

Standard Media Index (SMI), the advertising measurement firm which reports on 80% of US ad agency spending, reported that broadcast TV adspend was down -10% for the period while cable TV fell -3%.

Looking at the results for June, adspend was down -16% for broadcast while cable dropped -1%, but SMI attributed much of the decline to the boost the industry received last year from the 2014 FIFA World Cup.

The global footballing event generated more than $500m in TV ad revenue last summer, SMI reported. However, it said other factors could be in play.

"June's overall numbers were negatively impacted on a year-on-year basis by last year's World Cup," said James Fennessy, SMI's chief commercial officer.

"However, there are some underlying factors that are contributing to a deeper malaise," he added.

"Soft ratings and ongoing measurement issues continue to impact television's results and we also saw a slight slowdown in the explosive growth from digital, which points to marketers focusing more closely on return on investment."

Digital adspend posted double-digit growth in the second quarter, but it was up by just +17% in June compared to double that rate in April and May.

Overall US adspend increased +2% in Q2 2015, boosted in part by +16% growth in the out-of-home sector, but adspend remained flat in June amid signs that advertisers are holding back their spending to buy nearer to a broadcast date.

More positively, SMI also found that advertising on social media and video sites continued to grow consistently at +37% and +43% respectively.

Data sourced from SMI; additional content by Warc staff