Shares of Kinder Morgan Inc rose 3.5 percent above their initial public offering price on Friday as investors showed their appetite for the U.S. pipeline company's cash flow and yields.

The shares closed 3.5 percent higher than the IPO price of $30 at $31.05 on the New York Stock Exchange after the company conducted the largest U.S. energy-related IPO since 1998.

The IPO was seen as a means for Kinder's private equity partners to monetize their investment and an opportunity for investors to gain access to the company's track record of steady cash flows and its vast network of pipelines spanning the United States and stretching for 2,500 miles in Canada.

It's a yield play, Nick Einhorn, research analyst at Renaissance Capital, said of investor appetite. It's a high-quality company that still has pretty decent growth.

Backed by private equity investors including Carlyle Group and Goldman Sachs Group Inc's buyout fund, Kinder Morgan upsized its IPO as shareholders sold a 13.5 percent stake in the company.

Houston-based Kinder Morgan raised $2.86 billion on Thursday in an IPO valuing the firm at more than $21 billion.

INSTITUTIONAL INVESTOR APPEAL

Kinder Morgan's offering represented interest in its master limited partnership (MLP), Kinder Morgan Energy Partners LP , which holds most of the company's assets.

Historically, institutional investors have shunned buying into partnerships because of tax complications. But this offering was a way for them to add pipeline and storage assets to their portfolios as MLPs have low tax liability, which also provides them with a lower cost of capital.

It's a blue-chip from day one, said Francis Gaskins, president of IPODesktop.com. It's a blue chip that institutions have no problem owning.

The underlying MLP has forecast an increase of about 4.5 percent in its dividend yield this year, which would mean an even bigger yield growth for Kinder Morgan Inc investors, Einhorn said.

The IPO price of $30 per share implied a yield of 3.9 percent based on $1.16 per share in dividends Kinder Morgan said in the filing it would pay annually if it was public for all of 2011, analysts said.

Kinder Morgan's private equity investors and management will retain control of nearly 90 percent of the company.

Chief Executive Officer Rich Kinder, who led the 2007 buyout of the company, is keeping his entire 30.6 percent stake, which leaves him heavily invested in the company's future in contrast with typical private-equity investors' exits from a bought-out company through an IPO.

The CEO previously was president of energy company Enron Corp but left in 1996 -- years before it was enmeshed in an accounting scandal and went bankrupt.

IPO IMPACT

In the United States, Kinder Morgan owns 15,000 miles of natural gas pipelines and 8,400 miles of refined petroleum product pipelines running gasoline, diesel fuel, jet fuel and natural gas liquids. It also has 120 fuel terminals, gas storage facilities, carbon dioxide pipelines and stakes in eight West Texas oil fields.

The company's IPO became the biggest U.S. energy-related IPO since Conoco Inc's $4.4 billion offering more than a decade ago, according to Thomson Reuters data.

Pipeline investments could increase as power plants begin burning more natural gas instead of coal, as new shale gas sources are developed, or even to feed the need for facilities to export U.S. gas at cheaper prices.

Pricier crude could also lead to a greater need for more oil storage, as well as pipeline capacity for the output of quickly expanding projects in the Canadian oil sands.

Kinder Morgan Inc sold 95.5 million shares for $30 each in Thursday's IPO. It originally planned to sell 80 million shares at $26 to $29 each.

The upsizing followed an above-range IPO pricing by another private equity-backed company, Nielsen Holdings , and is a good sign for private equity firms looking to begin the process of selling portfolio companies bought during the height of the buyout boom of 2005 to 2007.

They will be judged on their own merits, but certainly ... two large successful private equity-backed IPOs is a positive for other companies looking to go public, Einhorn said.

Hospital operator HCA, which hopes to raise up to $4.6 billion, and retailer Toys R Us , which hopes to raise up to $800 million, are also expected to go public in the United States this year.

Underwriters on the Kinder Morgan offering were led by Goldman Sachs and Barclays Capital.

(Additional reporting by Braden Reddall in San Francisco; editing by Gerald E. McCormick, Phil Berlowitz, John Wallace)