US STOCKS-Wall St mixed as doubts about earnings offset biotech M&A bid

* Yahoo (NasdaqGS: YHOO - news) , Chipotle, Yum to report after the close

* Mylan (Berlin: 6MY.BE - news) shares up almost 10 pct after Teva bid

* Dow off 0.45 pct, S&P down 0.1 pct, Nasdaq up 0.48 pct (Updates to afternoon)

By Noel Randewich

April 21 (Reuters) - U.S. stocks were mixed on Tuesday, with the Dow industrials pulled down by a handful of uninspiring earnings reports, while the Nasdaq was pushed higher by a proposed biotech merger.

Travelers, DuPont and IBM (NYSE: IBM - news) shares weighed on the Dow. DuPont reported lower sales in all of its businesses and said a strong dollar would take a toll on its full-year earnings. IBM also mentioned currency effects when it reported a fall in revenue late on Monday.

DuPont was down 2.73 percent at $70.84 and IBM fell 1.14 percent.

March-quarter earnings season is in full swing, with almost 73 percent of the S&P 500 components that have reported so far beating bottom-line expectations, but just 42.2 percent beating expectations for revenue.

Investors are gauging how much a strong dollar has hurt U.S. multinationals, including technology companies like Facebook , Google (Xetra: A0B7FY - news) , Qualcomm (Swiss: QCOM.SW - news) , Microsoft (NasdaqGS: MSFT - news) that sell many of their products and services overseas and are expected to report their earnings this week.

"There's a lot of cross-current in the earnings picture. Are we at peak margins? Are we likely to hold, or might there be some downside?" said Mark Foster, chief investment officer at Kirr Marbach & Co in Columbus (Copenhagen: COLUM.CO - news) , Indiana. "People are pretty zeroed in on that."

The dollar has gained almost 9 percent since the beginning of the year against a basket of major currencies, hurting companies with large overseas operations.

Travelers reported a drop in quarterly net profit and its shares fell 3.73 percent.

At 3:04 p.m.. the Dow Jones industrial average fell 80.47 points, or 0.45 percent, to 17,954.46, the S&P 500 lost 2 points, or 0.1 percent, to 2,098.4 and the Nasdaq Composite added 23.74 points, or 0.48 percent, to 5,018.34.

Mylan shares rose 9 percent to $74.23 after Israeli drugmaker Teva made an unsolicited offer of $82 per share, in what could be the drug industry's largest takeover this year. Teva rose 1.91 percent. The Nasdaq Biotech index rose 2 percent.

Chipotle, Yahoo and chipmaker Broadcom were expected to report their quarterly results after the bell on Tuesday.

Advancing issues outnumbered declining ones on the NYSE by 1,552 to 1,466, for a 1.06-to-1 ratio; on the Nasdaq, 1,363 issues fell and 1,338 advanced, for a 1.02-to-1 ratio favoring decliners.

The S&P 500 was posting 12 new 52-week highs and no new lows; the Nasdaq Composite was recording 87 new highs and 24 new lows. (Additional reporting by Tanya Agrawal; Editing by Meredith Mazzilli and Nick Zieminski)