Southeast Asia's largest internet startups, Grab and Gojek, could be merging, according to a report from South China Morning Post.

According to sources familiar with the matter, both companies have made significant progress in working out a deal to combine their businesses, with SoftBank Group's Masayoshi Son being the key mediator between the talks.

Nothing has been concluded as of yet, but there is the possible outcome where both companies will be merged under one unified structure, with Grab's co-founder, Anthony Tan, being the chief executive of the combined entity.

Both brands will still continue to run separately for an extended period of time, but consolidation may take place in markets both brands compete in. In Indonesia, the combined entity will operate under the Gojek brand.

The ultimate goal of the merger would be to go for a public listing eventually.

Grab and Gojek have been locked in a fierce, expensive battle for dominance in becoming the region's "superapp", offering a wide range of services from ride-hailing, food delivery, and mobile payment services.

If the two companies do end up merging, this could be the largest internet merger in Southeast Asia.

Grab is presently valued north of $14 billion, while Gojek is valued at $10 billion.