The startup, which was valued at over $2.5 billion during its last fundraising round in October, is backed by Singapore sovereign wealth fund GIC Pte Ltd [GIC.UL], China's Ant Financial [ANTFIN.UL], and Korea's Shinhan Financial Group Co Ltd.

Bukalapak said in a statement that Zaky would be replaced from Jan. 6 by Kaimuddin, a finance executive who most recently was director of finance and planning for Indonesia's Bank Bukopin.

Zaky will establish a foundation and remain on as advisor, the firm said. Other co-founders Fajrin Rasyid and Nugroho Herucahyono will stay on as president and chief technology officer.

Surging smartphone use and rising middle-class income in a country of 260 million people have made Indonesia's e-commerce industry a battleground for foreign investors.

The archipelago's internet economy is Southeast Asia's fastest-growing and is likely to be worth $133 billion by 2025, according to a 2019 report by Alphabet Inc Google, Singapore state investor Temasek Holdings (Private) Ltd [TEM.UL] and global business consultants Bain & Co.

Bukalapak, which claims more than 70 million active users, previously told Reuters it expected to break even in three years' time, as it adds product segments and expands coverage in small towns.

It said it now serves more than five million micro and small enterprises across Indonesia and more than 2.5 million mom-and-pop shops and individual agents.

The company became a unicorn - a privately backed startup valued above $1 billion - after a fundraising round in late 2017.

(Reporting by Fanny Potkin; Editing by Simon Cameron-Moore)