Almost half of senior executives in the food and drink sectors have warned it will take the US economy at least until 2011 to "substantially recover", according to financial advisors KPMG.

In a survey, some 48% issued the bleak prognosis on the prospects for the US economy, KPMG said.

The findings, however, were mixed, with 72% of executives saying they were "optimistic" sales and earnings would improve in 2010. Some 60% said the US food and drink sector would recover fully "ahead" of the wider US economy.

Patrick Dolan, who leads KPMG's business with food, drink and consumer goods companies, said the results drew a "cautiously optimistic" picture.

"With the food and beverage industry in the midst of potentially disruptive change -  led by accelerating technological, social, and economic shifts - the executives surveyed are still upbeat about their future, though much hard work remains," Dolan said.

KPMG said some 58% of those surveyed believed finding new sources of revenue growth was the biggest challenge in the downturn. Some 52% pointed to the challenge of managing or cutting costs.