* Second reading of Q1 GDP up 1.2 pct vs est 0.9 pct
* Costco, Ulta Beauty rise on strong quarterly reports
* GameStop falls after sticking to full-year forecast
* Indexes down: Dow 0.09 pct, S&P 0.09 pct, Nasdaq 0.07 pct (Updates to open)
By Tanya Agrawal
May 26 (Reuters) - Wall Street was flat on Friday morning, coming off six straight days of gains and ahead of a three-day holiday weekend, as another strong day for consumer stocks was offset by weakness in financial and technology companies.
The consumer discretionary index was up 0.11 percent and the consumer staples index gained 0.6 percent, leading the gainers among the 11 major S&P sectors, after strong reports from a clutch of companies.
Shares of Costco Wholesale rose 2.2 percent to $178.61, giving the biggest boost to the S&P, after the warehouse club operator reported a strong profit.
Ulta Beauty jumped 4.7 percent, the most on the S&P, after the company raised its full-year forecast.
Deckers Outdoor Corp rose 15.4 percent to $65.56 after reporting a surprise quarterly adjusted profit. Big Lots was up 5.7 percent at $50.77 after the discount retailer raised its full-year profit forecast.
A strong batch of reports from retailers had also propelled the market on Thursday, when the S&P 500 and Nasdaq Composite closed at record highs.
The six-day winning streak is the market's longest since February and investors could aim to cash in their gains ahead of the long weekend due to Monday's Memorial Day holiday.
"The market is going to digest this move, people are going to take profits and are going to be a little cautious before the three-day weekend because, apart from all the good news, we still have potential for geo-political concerns that can come up at any time," said Andre Bakhos, managing director at Janlyn Capital in Bernardsville, New Jersey.
At 9:37 a.m. ET (1337 GMT) the Dow Jones Industrial Average was down 18.61 points, or 0.09 percent, at 21,064.34, the S&P 500 was down 2.25 points, or 0.09 percent, at 2,412.82.
The Nasdaq Composite was down 4.12 points, or 0.07 percent, at 6,201.13.
Six of the 11 major S&P 500 sectors were lower, with the technology index's 0.21 percent fall leading the decliners. The index has led most of the market's gains of late.
The markets' recent strength has been driven by strong quarterly earnings reports and the lack of major news updates on the political front, with President Donald Trump on his maiden presidential foreign visit.
However, with stocks at record levels and the earninsg season in the rear view mirror, analysts say the market needs to see progress on Trump's pro-growth policies, for the market to make further meaningful gains.
Earlier in the day, a report showed that the U.S. economy grew at a 1.2 percent pace in the first quarter, slightly more than the 0.7 percent growth estimated earlier. The higher reading was line with economists' expectations.
While recent economic data has been mixed, with data showing a dip in consumer spending and sentiment, a surge in business investment and wage growth suggests activity will regain momentum as the year progresses.
Among the laggards was GameStop, which fell 7.5 percent to $21.79 as the videogames retailer left its full-year earnings forecast unchanged despite its quarterly profit beating estimates.
Declining issues outnumbered advancers on the NYSE by 1,456 to 1,027. On the Nasdaq, 1,339 issues fell and 830 advanced.
The S&P 500 index showed 26 new 52-week highs and five new lows, while the Nasdaq recorded 26 new highs and 14 new lows. (Reporting by Tanya Agrawal in Bengaluru; Editing by Savio D'Souza)