SoftBank is reportedly pushing to take a multi-billion-dollar stake in Uber, people familiar with the matter told the Wall Street Journal. This comes one day after the Japanese tech company announced it was leading a $2.5 billion financing round in Uber's Southeast Asian competitor, Grab.

SoftBank's conversations with Uber were described as preliminary, and any deal would have to wait until Uber hired a new CEO to replace Travis Kalanick, according to the Journal. Neither Uber nor SoftBank responded to the Journal's request for comment.

An offer to Uber could signal that SoftBank is trying to acquire a wider share of the Southeast Asian ride-hailing market, which has become highly stratified in recent years.

In addition to a minority stake in Didi Chuxing of China, Uber operates in other Southeast Asian countries, including India, Singapore, and Malaysia. SoftBank already has an existing investment in Didi Chuxing; it is also a large investor in India's ride-hailing company, Ola. Plus, there's its recent investment in the Singapore-based startup Grab.

If SoftBank is indeed trying to take a larger slice of the market, it will need Uber to combine with competitors Ola and Grab, suggests the Journal. The San Francisco-based ride-hailing startup has done this in the past--most recently with its rival in Russia. Earlier this month, Uber said it would fuse its operations with Russia's Yandex Taxi and exit the country.

Tapping the Southeast Asian market would be extremely lucrative for SoftBank. The region's ride-hailing market could grow to $13.1 billion by 2025, a $10.6 billion increase from 2015, according to a report from Google and Temasek Holdings, a Singapore-state investment firm.