The deal, which eclipses Bombardier's previous record sale,$7.3 billion worth of Challenger planes to NetJets in June, sent Bombardier shares 8 percent higher.

"By any standard, this is a historic order for Bombardier," said Steve Ridolfi, president of Bombardier Business Aircraft, a unit of the Montreal-based plane and train maker.

VistaJet, which operates from London, Moscow, Dubai, Beijing and other locations, has placed a firm order for 56 jets worth $3.1 billion, with options on 86 more planes. Bombardier, the world's third-biggest planemaker, said deliveries are scheduled to begin in 2014.

The order's $7.8 billion value is based on 2012 list prices, but airlines typically negotiate steep discounts when they buy planes in bulk.

"This is the single largest transaction placed with any manufacturer in the entire history of business aviation," VistaJet founder and Chairman Thomas Flohr said at a press conference with Bombardier in London.

The planes will play a key part in VistaJet's expansion plans, he said, and its push to make business aviation more accessible in "embryonic" markets.

The aircraft will serve growth regions such as Russia, Kazakhstan, China, the Middle East and all of Africa, Flohr said, along with the U.S. East Coast and West Coast.

"VistaJet is a longtime Bombardier customer and exclusive operator of Bombardier business jets," said National Bank Financial analyst Cameron Doerksen. "The company had previously indicated that it was contemplating additional large orders, but the size of this order has to be considered a surprise."

VistaJet's firm order is for 25 Global 5000, 25 Global 6000 and six Global 8000 jets. The optional order is for 40 Global 5000, 40 Global 6000 and 6 Global 8000 jets.

The order will be spread out, Doerksen said, with the firm portion likely spanning seven years.

GAINING MARKET SHARE

"These orders reinforce the outlook for solid growth in production rates in the large-cabin business aircraft segment over the next several years," said BMO Capital Markets analyst Fadi Chamoun. "Bombardier continues to gain market share in business jets through strong product positioning."

Bombardier's Global aircraft compare favourably with rival planes on the key characteristics of cabin volume and flight range, said RBC Capital Markets analyst Walter Spracklin.

"The huge order from VistaJet establishes the Global as the predominate large-cabin, ultra-range business aircraft," he said.

It also serves to "shore up" Bombardier's business jet segment, bumping the Global production backlog well above the current 34 months, he added.

Bombardier shares jumped 8 percent, or 25 Canadian cents, to C$3.37 on the Toronto Stock Exchange on Tuesday. Year-to-date, the stock is down about 19 percent.

The VistaJet order comes three weeks after Bombardier pushed back the first flight of its new C-Series jetliner by six months due to delayed deliveries from suppliers, sending its shares lower.

Investors worried that Bombardier would not be able to meet its new deadline and that it would have to discount the aircraft to boost sales.

Doerksen said he remains cautious on Bombardier shares due to lingering uncertainty about the C-Series development schedule, the potential for weaker margin guidance when the company reports fourth-quarter results, and the risk that weak free cash flow will linger through 2013. (Additional reporting by Rhys Jones and Isla Binnie; Editing by Neil Maidment, Lisa Von Ahn and Peter Galloway)

• A Permanent Economic Emergency