Phao Bounnaphol gave an exclusive mandate to FHP, a company that specialises in assembling turnkey projects. It has drawn up a formidable list of projects that it intends to manage over the next 10 to 15 years.
They include mines, reforestation, roads, bridges, hospitals, factories, two airports, a hydroelectric station and an artificial limb factory.
The total value, says the FHP director of projects, Ken Blackburn, is "at least $2bn, of which we would expect 60 per cent to come from the UK." Companies involved in the schemes include IT Power, an alternative energy specialist, Overseas Enterprises, which is part of the National Health Service, and Vessa, an artificial limb company.
Artficial limbs are the key to yesterday's signing. Last summer Frank Cook, Labour MP for Stockton North, toured South-east Asia as part of his work for a charity that looks after mine victims.
Like its neighbours, Vietnam and Cambodia, Laos is littered with mines from the Vietnam War.
Mr Cook decided the country, which has an annual per capita income of £150, needed massive infrastructural development to stop it being swamped by its larger neighbours. Thailand, the biggest, accounts for the vast bulk of investment.
"I thought Laos should get a fast-track introduction to western procedures," Mr Cook said. "As a result of my visit, I was able to introduce the Vice- Premier to a number of people in the UK, including Mr Blackburn."
Mr Cook used to be a construction project manager, and believed that FHP, which has three offices in Vietnam, had the best credentials to handle the development.
FHP is assembling financing packages that will be largely based on countertrade. Mr Blackburn says he has "a consortium of French, US and British banks and financial institutions" lined up.
Although Laos is very poor, it has huge reserves of minerals, including gold, silver and platinum, as well as high-quality timber.
These mineral assets can be used as collateral for initial financing, he says, and later as barter products.