NEW YORK - Alibaba Group Holding Ltd's shares are expected to surge in their first day of trading on Friday as many investors that received fewer shares than hoped lined up orders to buy what looks likely to be the largest IPO in history.

Floor traders at the New York Stock Exchange were getting set for the stock to begin trading, with the exchange continuing to match millions of share orders. Indications were for the stock to begin trading between $91 and $92 a share, a more than 30 percent increase from its $68 initial public offering price.

The pricing on Thursday initially raised $21.8 billion for the Chinese e-commerce company. Scott Cutler, head of the New York Stock Exchange's global listing business, told CNBC that underwriters would exercise their option for an additional 48 million shares, to bring the IPO's size to about $25 billion, making it the largest IPO in history.

"This is the biggest IPO the world has ever seen, so there's a celebratory mood on the floor, whether you like it or not," said Benedict Willis, director of floor operations at Sunrise Securities Corp on the NYSE floor.

Alibaba is nearly unknown to most Americans but is ubiquitous in China, where it is responsible for 80 percent of online sales. The company earned $3.7 billion in the 12 months ended March 31, 2014, up about $2 billion from the prior 12-month period.

The sale values the company at about $168 billion, more than American icons such as Walt Disney Co and Coca-Cola Co . Should the stock close at $90 on its first day, it would be worth about $220 billion, nearly the value of Procter & Gamble Co.

Jack Ma, a former English teacher, founded Alibaba in 1999 in his apartment. His personal fortune is more than $14 billion on paper, vaulting him into the ranks of such tech billionaires as Bill Gates and Jeff Bezos. The deal is also expected to make millionaires out of a substantial chunk of the company's managers, software engineers and other staff.

Alibaba's shares met with intense demand from investors, with 35 and 40 institutions each placing orders for $1 billion or more in shares. The big increase expected in shares would exceed the gain by U.S. IPOs in the second quarter, which rose an average 9.2 percent in their first day of trading, according to Renaissance Capital IPO Intelligence.

Mark Hawtin, portfolio manager of the GAM Star Technology Strategy, a portfolio for offshore investors, said he was excited about how Alibaba priced and was hoping to buy more shares at the open. However, he said he will not pay more than $90. A number of other investors suggested their threshold was about $90 as well.

One institutional investor who had been told he was going to get one of the top allocations only received one-third of his order, and said he planned on buying more as long as the stock was trading below $90 a share. "I was told everyone is disappointed," he said. "I have cooled off now."

"We did put in for the IPO and we are getting an allocation, though not the full allocation we put in for. We probably got about 10 percent of that," said Michael Matousek, head trader at U.S. Global Investors Inc in San Antonio.

J.J. Kinahan, chief market strategist at retail brokerage TD Ameritrade, said the firm is seeing customer orders amounting to about 70 percent of what it saw for Facebook, and about three times the customer orders it had for Twitter's IPO.

Alibaba Group's orange banners were festooned around the exchange, with its logo on NYSE computer screens. Ma was on hand at the trading floor to watch several long-time customers ring the opening bell at the exchange.

"I don't want disappointed shareholders, I want to make sure they make money," Ma said of the pricing, on CNBC, adding that he worries most when customers are happy.

With underwriters electing to sell more shares, the company's initial public offering becomes the largest in history, surpassing Agricultural Bank of China Ltd's $22.1 billion listing in 2010.

NYSE held extensive tests to ensure it would be able to handle heavy trading volume and kept a call going on Friday with periodic updates to note the indicated price range and to say that systems were working properly.

Alibaba chose the NYSE over rival exchange operator Nasdaq OMX Group Inc to list its shares in part because it worried about Nasdaq's ability to handle a massive IPO after Facebook Inc's botched market debut in 2012.