Wall Street rose Wednesday on some strong earnings and new deals, but not without a struggle, as mounting signs of a tougher lending climate again dogged investors.

The stock market, coming off Tuesday’s 226-point tumble in the Dow Jones industrial average, seesawed throughout Wednesday’s session. Ultimately, it drew confidence from better-than-expected quarterly profits at Web retailer Amazon.com Inc. and plane manufacturer Boeing Co., and acquisitions involving German engineering company Siemens AG and drug maker Merck & Co.

Still, some investors worry that deteriorating lending conditions will cork this year’s heavy stream of dealmaking. Buyouts usually involve taking on debt, and Wednesday, the banks raising funds for the turnaround of Chrysler Group had to postpone a $12 billion debt offer after investors balked at the deal’s terms, according to people familiar with the situation who were not authorized to speak publicly. (MORE)