Wall Street stocks ended mostly higher yesterday as another round of profit-taking drew bargain hunters into the market. The Dow Jones industrial average rose 51.57 points to close at 6,858.11, having recorded losses after surrendering a 40-point gain.

Bonds were almost unchanged despite a US Labour Department report that productivity improved 2.2 per cent in the final three months of 1996, the best quarterly gain in three years and a result likely to ease inflationary fears.

Advances outnumbered declines by a 10-to-9 margin on the New York Stock Exchange, with 1,315 up, 1,200 down and 825 unchanged.

NYSE volume totaled 480.59 million shares, against 467.54 million in the previous session.

The Standard and Poor's 500-stock list rose 4.16 to 789.59, and the NYSE's composite index rose 1.74 to 414.09.

The Nasdaq composite index fell 3.99 to 1,331.35, and the American Stock Exchange composite index rose 1.40 to 589.24.