Bentley chief, Wolfgang Durheimer, told Autocar, "We can’t do both those cars at the same time, because Bentley is still a small company and our resources are very stretched".
To help it decide, the company is currently running the numbers on both vehicles. The magazine believes that the British marque will make a decision in either 2016 or 2017, after the large Bentayga crossover is launched and bedded in.
With this timeline, the earliest that a sub-Bentayga or Speed 6 model could hit the market is either 2020 or 2021.
The Bentley EXP 10 Speed 6 concept made its debut at this year's Geneva motor show in March. With a tightly drawn body and a strict two-seat configuration, it's expected that the any production version of the Speed 6 would have little overlap with the Continental GT coupe.
If the Speed 6 does make it into production, it will be pitched as a competitor to the Ferrari F12 Berlinetta or its successor.
According to Durheimer, many of company's existing customers have implored Bentley to "just built it", in regards to the Speed 6. They also indicated that they would be happy own both a Speed 6 and a Continental.