The London Taxi Company has secured a deal with Ujra Holding Company for 200 black taxis after it initially ordered 200 in assorted colours.
Chinese car maker Geely bought the company, formerly known as LTI, for Â£11.4m in October, when the former owners went into administration.
The United Arab Emirates has also ordered 200 black taxis.
The company said all vehicles are on target for delivery by the end of the year.
On his return from Saudi Arabia, Peter Johansen, vice president of the London Taxi Company, said the cabs are growing in popularity in the Middle East.
He said: "We've got a very good business partner in the Middle East and he's developed the London Taxi concept into Riyadh in particular.
"People prefer to use our taxis over the local taxis because they're more comfortable and, in particular, in Saudi women are treated slightly differently from the westâ€¦
"Because our taxi provides a segregated  compartment, separate from the driver, ladies in Saudi are allowed to use our taxis on their own, whereas they're not allowed to use the local taxis."
The company has also confirmed it is in talks with Azerbaijan which currently owns 1,000 damson-coloured black cabs.
In March, the London Taxi Company said it would take on about 100 staff, in addition to its 107 workers, to restart production at the Coventry factory on Holyhead Road.
About 156 people lost their jobs when former owners Manganese Bronze Holdings went into administration.
A Coventry-based black taxi manufacturer is to sell 400 cabs to Saudi Arabia.