The owner of LBC and Classic FM has sunk deeper into the red as the collapse of commuting on the London Underground helped wipe more than two thirds off its billboard advertising business. 

Global, which recently hired Andrew Marr from the BBC, recorded a pre-tax loss of £226m for the year to March, compared with a £166m loss for the previous 12 months, as it grappled with the “unprecedented challenge”. 

Its losses exceeded those of the prior year, even though they included a writedown of £219m forced by the initial outbreak of coronavirus in March 2020. 

Over the subsequent 12 months Global’s turnover plunged 41pc to £434m. The billboard business bore the brunt, with sales down 68pc. 

Global rapidly built one of Britain’s biggest outdoor advertising empires through a series of acquisitions. They included the 2018 takeover of Exterion, which holds the £2bn contract for the London Underground until 2024, the world’s most valuable billboard deal. 

In its accounts Global said the recovery across outdoor business was “more positive” for its roadside and digital billboards, but the Tube contract “remained challenging”. 

Global’s radio arm was spared the worst, with sales down 12pc over the year after it quickly bounced back. 

Between April and June, radio revenues were down 42pc, but by the final quarter of 2020 were actually up 3pc on the previous year. 

The broadcaster was founded by Ashley Tabor-King in 2007 ago with financial backing from his father, Michael Tabor, a horse racing tycoon who remains its controlling shareholder. 

The accounts of Global, which has partly funded its expansion by borrowing £413m from banks, reveal that it repeatedly appealed to its lenders to relax the rules surrounding its debts through the year. 

The latest agreement allows the company to carry more debt with lower cash flow until later in 2022. 

Global declined to comment.