Berwin Leighton Paisner (BLP) and Pinsent Masons have won spots on a new panel set up by Heathrow Airport Holdings to deal with legal issues around the construction of its third runway.

The appointments come after a competitive tender process, which began last year after the controversial new runway received government approval last October.

Both firms have already been working with the airport's in-house legal team on the initial stages of the third runway, but their positions on the new panel have now been formalised.

The firms are understood to have been appointed due to their expertise in planning law. The BLP team working on the new runway includes planning partners Tim Smith and James Good, while the Pinsents team includes infrastructure planning head Robbie Owen and planning partner Francis Tyrrell.

Heathrow has also hired a head of legal for planning to oversee the project, with an announcement set to be made imminently.

Heathrow Airport Holdings' legal panel consists of 11 sub-panels: corporate, finance and taxation; regulation, competition and procurement; commercial, IT/IP and construction; trademarks/IP registration; litigation; property and planning; property management; employment and pensions; debt collection; routine commercial; and Scottish airports.

The roster was last reviewed in 2013, with both Pinsents and BLP named on the property and planning sub-panel alongside Eversheds and Herbert Smith Freehills.

In total, Pinsents was appointed to nine of the 11 sub-panels, with BLP taking spots on two.