Uber’s self-driving car unit has been valued at $7.3bn (£5.6bn), after receiving $1bn of investment by a consortium including Toyota and Saudi Arabia’s sovereign wealth fund.

With weeks to go until the loss-making San Francisco firm’s stock market float, expected to value the company at up to $100bn, Uber said it had secured new financial backing for its plans to develop autonomous vehicles.

Japanese carmakers Toyota and its compatriot Denso, a car parts supplier, will invest a combined $667m in Uber’s Advanced Technologies Group (ATG). The remainder will come from Japanese conglomerate SoftBank’s $100bn Vision Fund, whose largest investor is Saudi Arabia. Toyota and SoftBank are already major investors in Uber, with the latter owning 16%.

In addition to the consortium’s $1bn investment, Toyota will provide up to a further $300m over three years to help fund ATG’s development of commercially available self-driving cars.

A new independent ATG board will be formed using the investment from SoftBank, Toyota and Denso. Six directors will be appointed from Uber, one from SoftBank and one from Toyota. Eric Meyhofer, the head of ATG, will be the chief executive.

Uber’s chief executive, Dara Khosrowshahi, said the funding would “help maintain Uber’s position at the forefront” of a transforming transportation industry.

It will also allow Uber to share the cost of developing self-driving cars with investors, allaying concerns about the amount being spent on a project that has shown few signs of bearing fruit. ATG has spent more than $1bn since 2016, a substantial outlay given that Uber has yet to make a profit and is not forecast to do so in the short term.

Appeasing Wall Street has become particularly important for the company, given that its stock market float is due to go ahead in early May.

It is expected to launch an investment roadshow at the end of April, which will explain to investors why they should put their money into the company. This is a critical process before an attempt to raise $10bn, leading to an expected valuation of up to $100bn.

One of the biggest concerns for potential investors is how Uber, which made a loss of $1.85bn last year and $2.2bn the previous year, intends to turn its rapid growth and globally recognised brand into regular profitability.

Long-term investment in self-driving vehicles is one potential route into the black because it would allow Uber to cut out the cost of paying its drivers. But in a regulatory filing before the float, it said ATG, which is yet to bring in revenue, is fast eating up investment cash.

Uber said developing self-driving cars was “expensive and time-consuming and may not be successful”. It is already lagging behind competitors such as Waymo, owned by Google’s parent company Alphabet, the company added.

The autonomous vehicle industry has been slow to get off the ground, with Uber suffering particular difficulty after a fatal crash in March 2018. The accident, involving an Uber self-driving SUV, killed a pedestrian in Tempe, Arizona, and forced the company to close its biggest testing operation and halt autonomous driving in other cities.

Uber has a small number of cars being tested in Pittsburgh but only during the day and in clear conditions, with two safety drivers present. They do not offer rides to passengers.

ATG’s chief scientist, Raquel Urtasun, said earlier this month that it is not clear when self-driving cars will be deployed at a large scale and for at least the next decade there will be a mix of robot and human-controlled cars.