(Updates at market close)

*

TSX ends down 0.1% at 29,731.98

*

Tech sector falls 2.5%

*

Constellation Software ( CNSWF ) loses 6% as president resigns

*

Materials group adds 1.1%

By Fergal Smith

TORONTO, Sept 25 (Reuters) - Canada's main stock index

ended lower on Thursday for a third straight day as technology

shares lost ground, but the commodity-linked market's decline

was limited after data showed stronger-than-expected growth in

the U.S. economy.

Toronto's S&P/TSX composite index ended down 24.97

points, or 0.1%, at 29,731.98, extending its pullback from a

record closing high on Monday.

U.S. gross domestic product increased at an upwardly revised

3.8% annualized rate in the second quarter amid strong consumer

spending and business investment.

"We really have this dynamic that there are a lot of

concerns but the risks have been pushed back just because of

(consumer) spending ... and there's potential for that momentum

to continue and for the Q3 numbers to show strength as well,"

said Ben Jang, a portfolio manager at Nicola Wealth.

The Atlanta Fed's GDPNow model has estimated U.S. annualized

growth of 3.3% in the current quarter.

Canadian GDP data for July, due on Friday, is expected to

show the economy expanding by 0.1% compared to the previous

month.

The technology sector fell 2.5%, with shares of Constellation

Software ( CNSWF ) down 6% as company president Mark Leonard

resigned for health reasons.

"He's extremely well regarded in the community. His name

carries a lot of weight," Jang said. "The firm has a very strong

culture and a really structured process for capital allocation

so they should be able to continue fine without him as

president."

BlackBerry was a bright spot. Its shares rose 9.1%

as the company raised its annual revenue forecast.

The materials group, which includes metal mining

shares, also advanced. It rose 1.1%, as the price of gold

moved closer to its recent record high.

Lithium Americas ( LAC ) added to its sharp gains the day

before, ending up 23.1%.