The stock market tallied a small advance today as a two-day rally faltered and then gained steam late in the session. The gain came despite a report indicating some weakness in the economy and despite a pronouncement that oil prices may rise even more than already scheduled.

The Dow Jones average of 30 industrials, ahead by more than 4 points at noon and down by .69 a half-hour before the 4 p.m. close, finished the day up by 1.13 at 749.79, continuing Tuesday's and Wednesday's slight gains. Advances led declines by about 3-2 among New York Stock Exchange-listed issues, and Big Board voulme rose to 28.67 million shares from Wednesday's 26.25 million.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the counter market, came to 32.74 million shares.

In the wake of Monday's 17.84-point Dow Jones drop, "the market is just holding," said Charles Jensen at MKI Securities. "That in itself is a constructive thing."

"There's still a lot of caution around." said Jensen. "People aren't yet convinced that the bottom has been reached."

In today's economic news, the Commerce Department said new orders for durable goods dropped by .9 percent in November. The drop came amid widespread predictions of an economic slowdown in 1979.

Late in the day, Canada announced a 4 percent boost in its export prices for crude oil. Its move followed an announcement by Rene Oritz, secretary general of the Organization of Petroleum Exporting Countries, the OPEC may decide to raise prices again before June. OPEC already has scheduled a 14.5 percent price boost for 1979.

After the market closed, the Federal Reserve announced a $100 million drop in the nation's basic money supply. Analysts said the drop may allow the Fed to ease its tight-money stand, although earlier predictions has expected continued tightening as an anti-inflation move. On Wednesday, Chemical Bank raised its prime lending rate 1/4-point to 113/4 percent, a shade below the record of 12 percent.

The NYSE's composite commonstock index rose .06 to 52.89, and the Amex market value index was ahead .94 at 148.34. Standard & Poor's index of 400 industrials advanced .04 to 105.49; the S&P 500-stock composite index rose .03 to 94.71.The NASDAQ composite index of tthe over-the-counter market rose 52 to 115.85.