* Now expects customer growth of 880,000 vs pvs forecast 800,000
* Q2 sales up 27 pct to 918 mln euros, in line with expectations
* Q2 EBITDA 178 mln euros, misses Reuters poll avg of 187 mln (Adds details on Business Applications IPO, divisions, forecast)
By Georgina Prodhan and Victoria Bryan
FRANKFURT/BERLIN, Aug 12 (Reuters) - Germany's United Internet raised its forecast for 2015 customer growth, saying it now expected more mobile Internet subscribers after investing heavily in customer acquisition.
The Internet service provider said on Wednesday it expected fee-based customer contracts to grow by 880,000 instead of 800,000, after a 430,000 increase to 15.2 million in the first half. It stuck to its sales and earnings forecasts.
United Internet has been aggressively investing for growth, spending close to 1 billion euros ($1.12 billion) in the last year on buying the rest of cable group Versatel, Polish web hoster home.pl and a stake in mobile rival Drillish.
It is also considering floating its Business Applications unit, which offers web hosting and other services to corporate customers, an announcement that positively surprised investors last month.
"The company plans to conclude its acquisition of home.pl in the second half of the year and begin examining the possibility of an IPO for its Business Applications," United Internet said on Wednesday.
The consolidation of Versatel helped lift second-quarter sales 27 percent to 918 million euros, in line with expectations in a Reuters poll.
Earnings before interest, tax, depreciation and amortisation (EBITDA) by 42 percent to 178 million euros, missing the average poll estimate of 187 million.
The strongest growth was in the company's Access segment for Internet connections, in which sales grew 37 percent and EBITDA 49 percent. In its smaller, Business Applications segment, sales grew 9 percent and EBITDA 24 percent.
United Internet - which competes with Deutsche Telekom , Liberty Global and a host of others for Internet customers - is forecasting 40 percent EBITDA growth and 20 percent sales growth for the full year.
The company added it expected proceeds of 13 million euros from the sale of part of its stake in digital advertising firm Virtual Minds to broadcaster ProSiebenSat.1 at the end of June. ($1 = 0.8951 euros) (Reporting by Victoria Bryan and Georgina Prodhan; Editing by Paul Carrel and David Evans)