The new funding round of at least $1bn from new and existing investors gives the five-year-old startup a valuation of up to $40bn, according to Bloomberg.
The new sum would mean Uber surpasses fellow Silicon Valley startup successes, including Twitter with a market cap of $25.6, LinkedIn at $27.7 and Netflix at $21.4m.
Uber would also more than double its previous record valuation of $17bn for a direct investment in a US startup, and places it on a level pegging with Chinese mobile maker Xiaomi in the billion dollar startup stakes.
The latest reported round of funding, said to include new investor T Rowe Price Group and existing investor Fidelity Investments, comes after a series of controversies.
Most recently a senior executive was revealed to have suggested that the private lives of hostile journalists should be investigated. Uber’s outspoken chief executive Travis Kalanick later apologised for the remarks saying they were not representative of the company.