Coffee shop, restaurant and hotel owner Whitbread was able to accelerate revenue growth during the first half, posting a 12.9% improvement in sales in the second quarter, up from a 9.2% increase in the first three months of the year.On a like-for-like (LFL) basis, sales rose 4.8% in the 11 weeks to 18 August."Whitbread traded strongly in the second quarter with total sales growth of 12.9%, making us one of the fastest growing consumer facing companies in the FTSE100. This growth, combined with a strong like for like sales increase of 4.8%, underscores our shareholder value creation and exciting future growth potential," said chief executive Andy Harrison.The strong growth was helped by a massive 28.8% surge in total sales from its popular Costa coffee chain, representing LFL increase of 9.7%. Premier Inn registered a 12.5% increase in sales, 7.1% higher on a LFL basis, helped by a particularly strong London market.This was able to offset a more subdued performance in its Restaurants division (which includes Beefeater Grill and Table Table), which saw sales rise by just 0.7% in the period, down 1.6% on a LFL basis. " Trading in our Restaurants continues to be challenging, with customers being particularly price sensitive," Harrison said.Combined with the first quarter - which saw poor trading in April - total group sales rose by 11% in the 24 weeks to 18 August (LFL: +3.2%).BC