Ride-hailing startup Grab said on Tuesday it has raised $750 million from investors to expand in burgeoning Southeast Asian markets including Indonesia, as it aims to build its lead over US-based rival Uber in the region.

The new investments led by Japan's SoftBank Group raised the Singapore-based firm's total capital to more than $1.0 billion, it said in a statement.

Competition between Uber and local startups has grown fierce in Southeast Asia, home to more than 600 million people and a rising middle class.

Grab is considered the leading ride-hailing platform in the region, operating in nearly twice as many cities as Uber, with the startup claiming up to 1.5 million bookings a day.

Singapore state investment agency Temasek Holdings was an early investor in the firm. 

Grab said participants in the recent round of fundraising included both new and existing investors which it did not name, but reports last month said China's Didi Chuxing was among those planning to back the firm.

The two companies are already partners in an alliance that also includes India's Ola and US-based Lyft Inc, allowing users to book rides while travelling to a country covered by any of the four apps.

Grab chief executive and co-founder Anthony Tan said the latest investment was "the largest in the history of Southeast Asia consumer technology".

"We are particularly excited about the growth opportunity in Indonesia, where we see an almost US$15 billion market for ride-hailing services alone," he said.

The move follows Uber's decision to sell its business in China to Didi Chuxing last month, ending a ferocious battle for market share that cost both firms billions.

Grab operates in Singapore, Indonesia, the Philippines, Malaysia, Thailand and Vietnam. Its core product platform includes private cars, motorbikes and taxi-hailing services which are rapidly gaining popularity in the region.