stylistic:tone
Cost

The tunnel is a build-own-operate-transfer (BOOT) project with a concession. TML would design and build the tunnel, but financing was through a separate legal entity, Eurotunnel. Eurotunnel absorbed CTG/F-M and signed a construction contract with TML, but the British and French governments controlled final engineering and safety decisions, now managed by the Channel Tunnel Safety Authority. The British and French governments gave Eurotunnel a 55-year operating concession (from 1987; extended by 10 years to 65 years in 1993) to repay loans and pay dividends. A Railway Usage Agreement was signed between Eurotunnel, British Rail and SNCF guaranteeing future revenue in exchange for the railways obtaining half of the tunnel's capacity.

Private funding for such a complex infrastructure project was of unprecedented scale. Initial equity of £45 million was raised by CTG/F-M, increased by £206 million private institutional placement, £770 million was raised in a public share offer that included press and television advertisements, a syndicated bank loan and letter of credit arranged £5 billion. Privately financed, the total investment costs at 1985 prices were £2.6 billion. At the 1994 completion actual costs were, in 1985 prices, £4.65 billion: an 80% cost overrun. The cost overrun was partly due to enhanced safety, security, and environmental demands. Financing costs were 140% higher than forecast.