NEW YORK (AP) _ The stock market gained more ground in active trading today, climbing past the 2,500 level in the Dow Jones industrial average.

Dow Jones's average of 30 blue chips rose 16.58 to 2,513.55 by noontime on Wall Street.

Gainers outnumbered losers by about 9 to 7 in the overall tally of New York Stock Exchange-listed issues, with 778 up, 611 down and 440 unchanged.

The Dow Jones industrials flirted with the 2,500 mark Wednesday and Thursday, only to close below it both times.

However, it moved cleanly past that round-number landmark this morning, with the help of a strengthening dollar in foreign exchange and a decline in open-market interest rates.

Perecptions that the economy remains sluggish were reinforced this morning by word that housing starts fell 0.7 percent last month.

Analysts say the market has also benefited lately from impressive second- quarter earnings reports by several leading industrial companies.

Kenner Parker jumped 4 7/8 to 45 1/4 . Analysts said a $41-a-share bid for the company from New World Pictures prompted speculation that higher offers might be forthcoming.

Coca-Cola was a prime contributor to the Dow's gain, rising 2 1/4 to 47 1/4 . The company announced plans to buy back as many as 40 million of its common shares over the next three years.

Philip Morris, which reported strong second-quarter earnings Thursday, rose 2 to 97 3/8 .

The NYSE's composite index of all its listed common stocks gained .52 to 176.22. At the American Stock Exchange, the market value index was down .11 at 352.98.

Volume on the Big Board came to 105.71 million shares at noontime, against 104.27 million at the same point Thursday.