BERLIN, Germany – German e-commerce investor Rocket Internet said on Thursday it had made progress to cut losses at its main start-ups and reiterated that it expected three of them to turn profitable by the end of 2017.

Rocket Internet, which has seen its shares slide on concerns about mounting losses, said the aggregate adjusted earnings before interest, taxation, depreciation and amortisation (EBITDA) margin of its top start-ups rose to minus 17 percent in the first half of 2016 from minus 32 percent a year ago.

Revenues rose an average of 32 percent to €1.043 billion ($1.17 billion).

Rocket also said it has expanded its existing convertible buyback programme, saying it may spend an additional €85 million on convertible buybacks by Sept. 30, 2017.

By Emma Thomasson; editor: Eric Auchard.