In the first hour of trading, UPS shares were up $18 at $68 from its inital offering price of $50 per share.

UPS gained a place in the record books after it raised $5.47bn from the sale of 10% of its shares in New York on Tuesday.

The total raised from the sale of shares, trading in which begins on Wednesday, makes it the largest initial public offering ever in the US.

The Atlanta-based firm, which delivers 12 million packages each business day, is seen as being a beneficiary of the growth of shopping via the internet.

To date it has been the online stores - such as Amazon - which have grabbed the vast valuations from the e-commerce explosion.

But with the growth of buying and selling of goods over the internet, UPS is seen as likely to be one of the firms well placed to pick up a large slice of the growing delivery business.

Helane Becker, an analyst with Buckingham Research Group, called UPS "a transportation internet stock."

Employees watching closely

The share issue was ten times over subscribed on the institutional side with the 109.4 million shares finally priced at $50, above the upwardly revised price range.

Analysts said UPS was an instant blue chip on Wall Street, which likes the company's strong performance record and future online prospects.

The previous largest IPO in the US was $4.4bn when oil company Conoco went public in October 1998.

With the money raised, UPS aims to make acquisitions in logistics, distribution and electronic commerce.

Its familiar name and long history have attracted strong demand and has led to expectations that UPS stock will deliver in its debut on the New York Stock Exchange Wednesday.

Many hot Internet companies have logged several-fold gains on their debut. Although industry watchers do not expect a similar rapid rise, they see solid gains for UPS.

UPS is the largest express-delivery firm in the world, 92-years-old, with 1998 income of nearly $2bn.

Wall Street wasn't alone in getting excited about the IPO.