By KATE LINEBAUGH, GINA CHON and VIPAL MONGA

Times may be tough for companies with poor credit, but for well-heeled corporate borrowers it's a different world.

Greg Hayes, chief financial officer of United Technologies Corp., was inundated with calls from bankers around the globe after news broke that his company was in the hunt to acquire aircraft-components maker Goodrich Corp. In the space of a single weekend, he got unsolicited commitments for more than $100 billion in loans, according to a person familiar with the matter.

The flood of offers reflected bankers' eagerness to snap up a piece of a big deal. The company wasn't expected to use anywhere near that much money. Indeed, United Technologies said Wednesday that it had agreed to buy Goodrich for $16.4 billion.

But the episode shows that the big problem for banks—and the global economy—isn't a lack of money to lend. It's a shortage of solid borrowers.

"This is not like 2008-2009, where there was truly paralysis of all the credit markets," said Deane Dray, a research analyst at Citigroup. "Better-capitalized companies which have easier access to very low-cost financing can use this as a growth opportunity."

At the opposite end of the credit spectrum, the situation could hardly be more different. Market volatility and fears of a spreading European debt crisis have put the brakes on financing for riskier deals, such as leveraged buyouts, which typically involve a big chunk of debt. Banks, afraid tough credit markets could leave them overexposed, are being more selective about the deals they back.

Thursday's steep drop in the stock market spooked some bond investors like Andy Johnson, head of fixed income at fund manager Neuberger Berman. But he said investors still are looking for debt that carries higher yields than U.S. Treasurys without too much risk, making an A-rated credit like United Technologies attractive.

J.P. Morgan Chase & Co. is leading the financing for United Technologies' acquisition of Goodrich, which includes a $15 billion one-year term loan. HSBC Holding PLC and Bank of America Corp.'s Bank of America Merrill Lynch unit also are involved in the loan package. United Technologies said Thursday that it expects to pay an average of less than 3% in annual interest on its borrowings for the deal.

"Financing activity has stayed strong for investment-grade companies," said Andy O'Brien, co-head of syndicated and leveraged finance at J.P. Morgan. "There is plenty of liquidity to finance large corporate M&A activity."

Highlighting the importance these days of a solid credit rating, United Technologies is taking the painful steps of selling $4.2 billion in stock and suspending share buybacks, for fear that the new debt it is taking on for the acquisition might otherwise trigger a downgrade.

"Keeping the credit rating especially in times like this, I mean it is sacrosanct," Mr. Hayes said on a conference call Thursday.

Many companies still have record amounts of cash on their balance sheets and are finding acquisitions an avenue for growth, deal makers said. United Technologies, for example, is extending its product lines by buying a business that doesn't overlap much with its own.

Earlier this year, J.P. Morgan, with an almost $2.3 trillion balance sheet, agreed to provide $20 billion in financing for AT&T Inc.'s proposed $39 billion takeover of T-Mobile USA. If the deal closes with J.P. Morgan as the sole lender, it would represent the largest single-bank loan funding for a takeover in history and would be the bank's biggest loan ever.

In Hewlett-Packard's $11 billion deal to buy U.K. software company Autonomy, Barclays Capital is the sole bank behind an $8 billion loan package needed to seal the transaction.

To finance United Technologies' purchase of Goodrich, the banks will assemble a 364-day loan commitment. The acquiring company rarely draws on such a loan. Rather, it is considered a "bridge" to tide the company over until it can sell bonds or stock to finance the deal. But if a company is unable to raise such funds, banks can be left with a hefty exposure to a single company, which is why United Technologies' high credit-rating helped draw so much interest.

United Technologies plans to raise about $12 billion in a bond sale before the deal closes, which is expected to happen in the middle of next year. It would be one of the biggest bond sales in the recent years. The last bond deal of more than $10 billion took place in March 2009, when drug maker Pfizer Inc. sold $13.5 billion of bonds.

Since 2000, just 10 U.S.-dollar denominated bond offerings have exceeded $10 billion, according to Dealogic.