"Corporate earnings have come roaring back so fast that it would seem the business environment can't get much betteryet some signs suggest profits won't weaken anytime soon.</br></br>Second-quarter earnings of major U.S. companies blew past analysts' estimates. Setting aside the effect of cable-TV provider MediaOne Group's extraordinary gain last year of about $24.5 billion, income at the 654 companies that make up the U.S. part of the Dow Jones Global Indexes rose 37% in the second quarter from a year earlier. MediaOne's gain, from its separation from U S West, skews the year-to-year comparison; including the gain, net income was up 5%.</br></br>Other one-time events, such as writeoffs and gains from the sale of affiliates, and easy comparisons against year-earlier results weakened by restructuring charges boosted the companies' net income. But even operating income, which excludes such items, rose 15% from the second quarter of last year, according to calculations done by First Call/Thomson Financial for The Wall Street Journal.</br></br>In the 1999 first quarter, net income was down 6%, while operating income rose 9.6%. Analysts who wondered early this year if the rebound in first-quarter operating profits was a fluke now know for sure that it wasn't; business is better for a broad swath of corporate America.</br></br>""The bottom line is that business is good and we expect it to continue for a while,"" says Chuck Hill, director of research at First Call, which tracks corporate earnings. ""We're in a period of accelerating earnings growth that will peak out in the third quarter, but we still expect earnings to stay strong."""