REFILE-US STOCKS-Swiss bank rules send futures down ahead of dat

(Fixes typo in 8th paragraph, "factory" instead of "factor")

* Switzerland seeks new rules for Credit Suisse, UBS

* Microsoft lower after Goldman downgrade

* Sanofi launches Genzyme bid

* Futures down: Dow 47 pts, S&P 3.3 pts, Nasdaq 4.75 pts

* For up-to-the-minute market news see [STXNEWS/US] (Adds quote, updates prices)

By Ryan Vlastelica

NEW YORK, Oct 4 (Reuters) - U.S. stock index futures were lower on Monday after a Swiss plan to tighten banking rules raised fears of smaller bank profits ahead of a new round of U.S. data.

Switzerland will seek rules to require global banks UBS AG and Credit Suisse to hold more top-quality capital. The potential regulations, stricter than recently proposed international standards, could crimp the banks' competitiveness in investment banking. For details, see [ID:nLDE6920GP]

The FTSEurofirst 300 <.FTEU3> index of top shares was down 0.3 percent, though U.S.-listed shares of Credit Suisse and UBS were little changed in premarket trading.

Concerns about Europe's banking system have been a headwind for U.S. stocks in recent months even as some improving domestic data eased concerns over a possible double-dip recession.

The Swiss move "could be an inflection point where markets begin to get more worried about Europe," said James Dailey, portfolio manager of TEAM Asset Strategy Fund in Harrisburg, Pennsylvania.

"I don't expect this will have us break below the bottom end of the trading range we've been in, but these are economically sensitive issues that continue to percolate."

The S&P 500 recently finished its best quarter in a year, though the index has struggled to break out of the 1,130-1,150 range.

Monday's economic data includes pending home sales, durable good orders and factory orders, all for August. Home sales are seen rising 3 percent after rising 5.2 percent in the previous month. The closely watched non-farm payrolls report for September will be released on Friday and will offer insight into the labor market, which continues to be an economic headwind.

S&P 500 futures dipped 3.3 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures fell 47 points, and Nasdaq 100 futures lost 4.75 points.

Microsoft Corp fell 1.9 percent to $23.91 in premarket trading after Goldman Sachs downgraded the Dow component to "neutral" citing competition from tablet computers. [ID:nSGE6930CY]

French drugmaker Sanofi-Aventis SA launched a hostile bid for Genzyme Corp at $69 per share, taking its offer directly to shareholders after the biotechnology company refused to negotiate. [ID:nLDE69302S]

In other deal news, Actel Corp surged 28 percent to $20.50 in light premarket action after Microsemi Corp , said it would buy the integrated circuit manufacturer. GTSI Corp tumbled 44 percent to $4.08 after Eyak Technology withdrew an offer to buy the company. [ID:nSGE69306B] and [ID:nWNAB1405]

While no S&P 500 companies are on tap to release results on Monday, this week marks the unofficial start of the third-quarter reporting season, with Alcoa Inc due on Thursday. Micron Technology Inc , PepsiCo Inc and Monsanto Co are all set to report this week.

Wall Street extended a rally on Friday, led by gains in natural resource stocks after data in China showed a pickup in manufacturing activity. (Editing by Jeffrey Benkoe)