SINGAPORE - Indonesian ride-hailing and payments firm Gojek and e-tailer PT Tokopedia are in advanced talks for a $18 billion merger that they aim to seal in the first half of 2021, two people with knowledge of the matter told Reuters on Tuesday.

The merger would bring together two of the country's most valuable start-ups. The people said the merged entity would seek a joint listing in Jakarta and the United States.

One of the people said the pair signed a term sheet in late December enabling them to conduct due diligence of each other's business. The person said no deal had yet been agreed.

Separate people previously said investors in Gojek and bigger rival Grab backed a merger of both Southeast Asian firms, but that a deal was far from finalized.

All the sources declined to be identified due to the confidential nature of the talks. Gojek and Tokopedia did not immediately respond to Reuters' requests for comment.

Bloomberg News earlier reported merger talks between Gojek and Tokopedia. (Reporting by Anshuman Daga in Singapore and Radhika Anilkumar and Ann Maria Shibu in Bengaluru; Editing by Ramakrishnan M. and Christopher Cushing)