By Anshuman Daga, Aradhana Aravindan and Jonathan Weber

SINGAPORE (Reuters) - Singapore-based ride-hailing firm Grab is set to invest "several hundred million dollars" in Vietnam where the company sees its next major growth market, just weeks after it unveiled a $2 billion plan in Indonesia.

The proposed investment is the latest example of a top-notch regional brand deepening its commitment to Vietnam, one of Asia's fastest growing economies. It also shows the eagerness of Grab, which has raised billions of dollars from investors, to put its cash to work.

"We're very excited about Vietnam. We see very similar characteristics to Indonesia," Grab President Ming Maa told Reuters in an interview.

Grab and rival Indonesia-based Go-Jek are evolving from ride-hailing app operators to become one-stop shops for services as varied as payments, food delivery, logistics and hotel bookings in Southeast Asia.

Grab, with its app on more than 160 million mobile devices across eight countries, has said its Indonesia investment aims to build a next-generation transport network and transform how critical services such as healthcare are delivered.

Like Indonesia, many middle class and young consumers in Vietnam are using apps and websites to access services, Maa said.

"I would expect us to invest over several hundred million dollars into growing our Vietnam business," he said without giving specific details on the investment.

Vietnam ranks third or fourth among Grab's top markets, said Maa, who joined the company three years ago from its major investor, Japan's Softbank Group Corp, and a previous decade-long stint at investment bank Goldman Sachs.

Grab partnered with Vietnamese fintech firm Moca in 2018 to launch a digital wallet. Grab formed a joint venture with Credit Saison, a Japanese credit card company, last year to offer loans and credit analysis to consumers and micro-entrepreneurs across Southeast Asia.

Grab was Vietnam's most downloaded ride-sharing app from January to July, according to market data and analytics firm, App Annie. Aside from Go-Jek, Be is another ride-hailing competitor.

The wealthy city-state of Singapore is Grab's second-biggest market, where it is building a $135 million headquarters. The company, which has over 4.5 million drivers in the region, aims to double its revenue to $2 billion this year.

Maa said its total gross merchandise volume (GMV) in food delivery, a segment where it is expanding aggressively, has surged 300% in the first half. GrabFood now accounts for 20% of the company's total GMV.