* Caution on bank stress test results to weigh

* Exxon, Pfizer and others due to post results

* Federal Reserve set to hold policy meeting

* World swine flu epidemic risk grows (Updates with latest on swine flu)

By Ellis Mnyandu

NEW YORK, April 26 (Reuters) - U.S. stocks may run into some turbulence this week as the impending release of bank "stress test" results, a Federal Reserve meeting and a flood of earnings give investors reasons for caution.

Fears of a global swine flu pandemic developed into another factor to watch over the weekend with new infections in the United States and Canada discovered on Sunday, and as millions of Mexicans hid indoors to avoid a virus that has already killed up to 81 people. For details see [ID:nN26482522].

But investors said that as this point, news on the state of the financial system and earnings would drive sentiment and that information about the illness was too sparse to influence the New York open on Monday. News of the flu spreading, however, could weigh on the market as the week progresses.

While investors have been heartened by a recent flurry of surprisingly upbeat earnings and economic data, strategists said there was still concern about whether the government has done enough to shore up the banking sector.