The 7km central section of Line 3 from Botevgradsko Shosse to Ovcha Kuptel will have seven stations and construction will be divided into four lots. The project is due to be completed within 45 months of contract signing.

When all phases are complete, the line will run for 16.5km from Vassil Levski in the east to Knazyhevo in the west, interchanging with Line 1 at St Clement and Line 2 at NDK.

The project is expected to be co-financed by the European Union.