The corporate bond market caught a huge gust of wind in its sails on Tuesday, as companies lined up to raise financing for everything from funding acquisitions to buying back stock.

Four companies - DuPont Co. (DD), Union Pacific Corp. (UNP), Coca Cola Enterprises Inc. (CCE) and Honeywell International Inc. (HON) - raised a total of $3.75 billion in the investment-grade market Tuesday.

Meanwhile, Swiss pharmaceutical company Roche Holding AG (RHHBY) is in the market via Roche Holdings Inc., with a four-part bond offering that market participants expect to total at least $1 billion, but likely far more. That offering is likely to price on Wednesday.

A $5 billion-plus bond issue isn't inconceivable for AA-minus-rated Roche, given that BBB+ rated Anheuser-Busch InBev (ABI.BT), the world's biggest brewer, raised $5 billion in the debt capital market in early January.

Roche, which is also seeking financing in Europe, is lining up funds for its approximate $40 billion cost of acquiring the outstanding 44% stake in U.S. biotech company Genentech Inc. (DNA), in which it already holds a 56% interest.

While Roche wouldn't comment on specifics of the upcoming transactions, a spokeswoman did say that "the company is confident that we can raise the financing needed to complete the combination of Roche and Genentech."

Meanwhile, Honeywell sold a $1.5 billion two-part offering, including $900 million of 10-year bonds and $600 million of five-year notes. Atlanta-based Coca-Cola Enterprises sold a combined $600 million in debt and chemical maker DuPont sold $900 million of senior notes, also in two parts. Transportation company Union Pacific raised funds to partially fund its share repurchase program.

Companies are hurriedly tapping the market in order to obtain financing while the climate remains issuer friendly - combining low rates with heavy demand.

"Today's action will go toward general corporate purposes as we take advantage of the current attractive rates," said Anthony R. Farina, DuPont's director of global public affairs.

Some investors spurned by the plunge in stock prices have turned their backs on equities and are finding an alternative in the debt markets, where returns are exponentially more promising than those in the stock market.

"The bond market has become a more viable investment option than the stock market," according to Bill Larkin, fixed-income portfolio manager at Cabot Money Management.

Larkin added that doubts about the government's rescue package and bailout plan have caused a slide in stock prices, and portfolio managers have moved away from equities and toward bonds. "Money is looking for a safe place to go, and higher-quality corporates outside of banks and finance are benefitting from that."

Last week, $15 billion of fresh corporate debt was snapped up, confirming that the corporate bond market is very much open for business and that cash-heavy buyers are clamoring for more.

The corporate bond sector has recently outperformed other areas of the credit markets and is currently providing a cushy issuing environment for sellers via low Treasury yields amid heavy investor demand.

Moody's Investors Service's capital markets research group said Tuesday they expect U.S. corporate bond issuance to increase by 7% in 2009, propelled by a successful FDIC-backed short-term issuing program and attractive financing costs for borrowers.

So while companies that were shut out of the new-issue market just a short while ago are now able to obtain financing at reasonable cost, investors are right behind scrambling to get a piece of the action.

With diversification key, money managers are also benefitting from some slight competition.

The $750 million Union Pacific deal included a change-of-control provision, which allows bondholders the option of selling back their bonds at a premium to the company in the event of a takeover or sale.

In late 2006 and early 2007, bond buyers demanded covenants be included in the language of bond contracts, offering holders protection against the biggest threats back then - leveraged buyouts and ratings downgrades. But during the current issuing frenzy, covenants are being considered more of a bonus than a necessity.

"That's a pendulum that swings both ways," Larkin said. "They're added to sweeten the deal. The company is adding tidbits to make it more attractive and get my attention." Larkin said the provisions put a positive twist on standout issues in a seemingly competitive market.

-By Kellie Geressy, Dow Jones Newswires; 201-938-2050; kellie.geressy@dowjones.com

(Carol Dean and Michael Aneiro contributed to this report.)