US STOCKS-S&P 500, Nasdaq set for 6th straight quarter of gains

* S&P 500, Nasdaq to add to string of quarterly gains

* BNY Mellon stock rises after Trian discloses stake

* MannKind (NasdaqGM: MNKD - news) rallies on FDA's approval of inhaled insulin

* Dow down 0.1 percent; S&P 500 flat; Nasdaq up 0.3 percent (Updates with GM (NYSE: GM - news) shares; updates prices)

By Angela Moon

NEW YORK, June 30 (Reuters) - U.S. stocks barely moved on Monday after a set of mixed economic data, but the S&P 500 and Nasdaq Composite indexes were set to close a sixth straight quarter of gains, a streak not seen in more than 14 years.

Following the S&P 500's 30 percent gain last year, many investors had expected a halt to an equity bull market that is now in its fifth year.

Utilities represented the S&P 500's best-performing sector in the second quarter of the year, while the retail sector was among the weakest.

The S&P 500 has scored 22 record closing highs so far this year, which has increased concerns among some investors that the market might be due for a technical pullback. Yet the CBOE Volatility Index, Wall Street's fear gauge, has held near multi-year lows.

A recent Reuters poll showed market participants expect the benchmark S&P 500 to hit 2,000 for the first time before the year ends. That milestone would mark a gain of about 8.2 percent from 2013.

The Dow Jones industrial average fell 15.44 points or 0.09 percent, to 16,836.4, the S&P 500 gained 0.84 point or 0.04 percent, to 1,961.8 and the Nasdaq Composite added 14.75 points or 0.34 percent, to 4,412.68.

"We still think a move into the 1,980-2,000 level is possible, but it will not be a huge surprise if 1,950 is revisited multiple times as we move through the summer months," said Todd Salamone, senior vice president of research at Schaeffer's Investment Research in Cincinnati.

On Monday, the market barely reacted after data showed the pace of business activity in June in the U.S. Midwest dipped more than expected from a seven-month high, and contracts to buy previously owned U.S. homes hit an eight-month high in May.

With an abbreviated week due to the Independence Day holiday on Friday and a ream of data due Wednesday and Thursday, there may be increased volatility in a market that, some traders say, has been frustratingly placid.

Barring a late market slide on Monday, the S&P 500 and Nasdaq will close up for a sixth straight quarter. That is the longest streak of quarterly advances for the Nasdaq since 2000, while for the S&P 500, it is the best run of quarterly gains since 1998. The Dow is on track for its fifth positive quarter of the last six.

Shares of General Motors were down 1.7 percent at $35.99 in late afternoon trading after the automaker announced six more safety recalls.

Bank of New York Mellon shares rose 2.7 percent to $37.22 after Trian Fund Management disclosed in an amended filing a stake of more than nine million shares of the bank.

Shares of MannKind Corp surged 11 percent to $11.11 following the U.S. Food and Drug Administration's approval on Friday of Afrezza, the company's inhaled insulin product. The FDA said the inhaled insulin, delivered via a whistle-sized inhaler, offered a new treatment option for patients with diabetes.

Investors kept watch on news from the Middle East as Iraqi troops battled for Tikrit after the leader of an al Qaeda splinter group was declared caliph of a new Islamic state in lands seized this month across a swath of Iraq and Syria. (Reporting by Angela Moon; Editing by Jan Paschal and James Dalgleish)