(ShareCast News) - Convenience food firm Greencore posted a 6.2% jump in third quarter revenues, but warned of challenges in the UK grocery market.Greencore recorded revenue of £346.5m, off £331.9m in revenue from in its convenience food division.In its core UK market, like-for-like revenue was 4% higher than in the prior year, while in the US like for like revenue was up 22.1%, the company said.Greencore said this was led by new product lines in the Northampton facility, and elsewhere growth was subdued.The company said the core UK grocery retail market remained challenging."The combination of modest deflation in ingredients and packaging costs, together with price investment by grocery retailers, has resulted in value growth lagging behind volume in a number of our product markets," Greencore said.The company said it was confident of delivering its earnings for the full-year within the range of market expectations."The group remains focused on delivering exceptional standards for its customers and on the execution of complex capacity increase projects in both the UK and US."We remain confident in our ability to deliver adjusted EPS growth for the financial year within the range of market expectations," Greencore said in a statement.Shore Capital said in a note to clients that it retained its earnings per share forecast of 17.4p, while the consensus range was 17.2-18.3p.Analysts described the update as "solid" and kept a 'hold' rating on the stock and price target of 318p.