The stock market moved lower yesterday as profit taking ate up some of the previous week's gains.

The Dow Jones index of 30 industrials, which was ahead by more than 3 points at midday, closed down 3.38 at 885.05. Volume on the New York Stock Exchange totaled 33.35 million shares, against 37.91 million on Friday, but advances just outpaced declines among NYE-listed issues.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over the counter market, amounted to 37.20 million shares.

The Standard & Poor's index of 400 industrial stock fell 0.49 point to 114.46. S&P's 500-stock composite index dropped 0.37 point to 104.84.

After last Wednesday's 26.05-point surge in the Dow and Thursday's record-breaking 66.37-million-share NYSE volume, things were bound to cool, said Hildegarde Zagorski at Bache Halsey Stuart Shields Inc.

But Zagorski said Bach'e forecast that the Dow will reach the 900 marks "in a few weeks" still holds.

At the J. Henry Schroder Bank & Trist Co., meanwhile, analysts were noting less optimistically that despite last week's rally "the basic factors which ulitmately shape the behaviour of the markets" - including the outlook for inflation, interest rates and the dollar - have not changed appreciably in recent days.

Firestone Tire & Rubber was the most active NYSE-listed issue, off 7/8 to 12 3/4 following a block trade of 261.300 shares at 13 1/8. The company, which is undergoing a federal hearing about the safety of its radial tires, said it expected sharply lower 1978 earnings.

Ramada Inns was the day's second-most-actively-traded NYSE issue, rising 1 1/4 to 8 5/8. The company tied the activity to a prospectus for a $75 million debenture offering saying it plans to enter the gambling casinobusiness. Ramada Inns already owns an interest in casino operator Del E. Webb.

Pet Inc. was third, up 54 5/8 in trading that included a block of 312.900 shares at 54 5/8.

Tropicana, which completed its merger with Beatrice Foods after lengthy legal action, added 3/4 to 52 1/2 following a block of 280.000 shares at 52. Beatrice stock was unchanged at 25 7/8.

Boeing Corp. shed 3 7/8 to 69 1/2 in active trading after reporting second-quarter earnings of $1.82 a share versus $1.33 a year ago. Many investors were disapointed. But Wolfgang Demisch of Smith Barney. Harris Uphan remained upbeat on the firm, saying Boeing was spending heavily now on new aircraft for which it has received large orders.

Overnite Transportation rose 1 1/2 to 25 1/4. Company workers rejected representations by the Teamsters' union, according to balloting results released during the weekend.

Leaseway Transportation a 1 1/4 point winner Friday, jumped another 1 1/2 to 38 1/2. The company said it knew of no reason for the activity in its stock.

Geahart-Owen could not explain its stock's 2 1/2-point rise to 70.

Xtra Corp. climbed 2 1/8 to 45 7/8 after the company reported higher earnings, announced plans for a 5-for-3 stock split and proposed a higher dividend.

Loews Corp. added 1 5/8 to 51 1/2 after the company reported its second-quarter net had risen to $2.84 a share from $1.37 a year ago.

Dentsply dropped 1 1/8 to 22. The firm reported second-quarter earnings of 80 cents a share versus 61 cents a year ago. But the 1978 quarter included a foreign currency gain of 37 cents a share.

Belden Corp. rose 1 7/8 to 26. Barron's a financial weekly magazine, commented favorably on the firm.

On the Amex, advances topped declines by 353 to 298 among the 927 issues traded. Composite volume totaled 4.861.900 shares compared will 4.528.205 Friday.

Macrodyne Industries was the most active Amex issue, up 3/4 to 3. Loews Theatre warrants were second, up 1 5/8 to 21 7/8. APS Inc. was third, up 1 to 9 3/4 following a block trade of 163,200 shares at 9 1/4.

Resorts International A stock soared 3 1/3 to 87 1/2 after company directors voted for a 3-for-1 stock split on the common stock. Resort B stock gained 8 to 93.

New Hampshire Ball & Bearing gained 2 to 22 after the firm reported fiscal year earning of $3.34 a share compared with $2.23 a year ago.

In OTC trading, declines edged advances by 534 to 523 among the 2.506 issues traded. Volume totaled 12.800.500 shares compared with 12,858,300 Friday.