Aug 13 (Reuters) - German meal-kit delivery firm HelloFresh said on Monday it no longer expected to break even in the fourth quarter of this year as it plans to invest margin profits to support growth.

It added it now planned to achieve such break-even on adjusted earnings before interest, taxes, depreciation and amortisation (AEBITDA) basis during the course of 2019.

The company, which competes with struggling U.S. rival Blue Apron, said investments would include such measures as price reductions, increase in meal selections in the U.S. market and scaling up of a new value brand.

At the same time, HelloFresh raised its target for 2018 constant-currency revenue growth, excluding Green Chef, to 32 to 37 percent, from previously 30 to 35 percent, after reporting 48 percent growth in constant-currency revenues in the second quarter to 339.9 million euros ($387.21 million).

The margin on AEBITDA improved by 6.1 percentage points to negative 1.2 percent in the second quarter, the company said. ($1 = 0.8778 euros) (Reporting by Sylwia Lasek in Gdynia Editing by Maria Sheahan)