The world's biggest sovereign wealth fund, the Abu Dhabi Investment Authority (ADIA) is to make bid for the Channel Tunnel high-speed rail link, jointly with Morgan Stanley and private equity group 3i.

The sale, which is expected to bring 1.5 billion to 2 billion pounds, will to use to support Britain's huge debt pile.

The deadline for submitting an offer for the first round of bids is 17 August.

The government has put the sale of UK's only high-speed railway in June.

The 110-km High Speed 1 (HS1) line runs from St. Pancras station in central London to the Channel Tunnel and its sale, if successfully completed, will be the first major British transport infrastructure sale after the sale of Gatwick airport in London by BAA in the end of 2009.

ADIA has purchased 15 percent holding of Gatwick Airport in the beginning of this year.

The UK government has received around 15 applications to bid for HS1.

The other bidders include Channel tunnel operator, Groupe Eurotunnel, which is supported by its biggest investors, Goldman Sachs Infrastructure Partners and the infrastructure division of Prudential unit M&G, Infracapital.