Domino's Pizza reported growth in like-for-like sales in the first half across the UK, Ireland, Germany and Switzerland.The start-up German business grew steadily with like-for-like sales up 23.8% while the UK rose 6.4%, Ireland jumped 6.5% and Switzerland was up 7.8%.The company said it would take time to reach scale in Germany as the company builds brand awareness and opens enough stores to cover fixed costs."This process will take longer than originally expected," the firm said."It is important to remember that Domino's businesses round the world have taken some time to reach critical mass, before going on to be real profit generators."Profit before tax, excluding Germany and Switzerland, increased 10.3% to £25.7m. Including Germany and Switzerland, after exceptional items, it fell to £11.6m from £21.5m. System sales increased by 13.8% to £326.5m while margins, excluding Germany and Switzerland, rose to 21.2% compared to 20.9% the prior year.During the period, the firm opened 22 new stores, compared to 23 last year. There were two closures, compared to one closure in 2012, bringing the total number of stores to 825 at the end of June. Domino's raised its interim dividend by 7.6% to 7.10p per share. Canaccord Genuity reiterated a 'sell' rating for the stocks, saying it was risky and too expensive. Shares plunged 9.17% to 545p at 11:19 on Tuesday. RD