MIDLAND, MI —Dow Corning is reviewing global corporate PR duties for the first time in 18 years, in a move that brings a close to its lengthy relationship with APCO Worldwide.

The Holmes Report understands that the US MNC has contacted a number of global PR firms regarding the assignment, with a decision due before the end of the year. After 18 years, it is thought that both APCO and Dow Corning agreed to call time on the relationship.

The corporate communications mandate has long been considered one of APCO's key accounts, with annual spend rarely dipping below the seven-figure mark. However, it is understood that budgets have declined in recent years.

"After 18 years of partnership with APCO, Dow Corning has decided to initiate an agency review – the first during the length of our engagement," said APCO senior director Kelly Williamson.

"While the company is considering a new agency partner, we are continuing to work for them on important assignments around the world, and are deeply grateful for the long-standing relationship we have enjoyed with the company."

An equal joint venture between Dow Chemical and Corning, Dow Corning's silicone and silicon-based tech products earned the company sales of $5.71bn in 2013, representing a 7% decrease on 2012. The company has reported increased sales and profits for the first half of 2013.