JOHANNESBURG (Reuters) - South African stocks dropped 1 percent on Friday after U.S. and Asian equities fell and miners Anglo American and BHP Billiton dipped after merger rumours failed to materialise.

The Johannesburg Top-40 index of blue-chip stocks fell 1.03 percent to 25,220.42 points by 0750 GMT, while the All-share index fell 1.0 percent to 28,155.26 points.

"We are tracking weaker sessions in Asia and on Wall Street, where there are concerns about the retail numbers. We've seen our market run hard and people are taking this chance to take some money off the table," said Ferdi Heyneke, portfolio manager at Afrifocus Securities.

Heavily-weighted diversified miners dragged the market lower after they motored higher earlier in the week on talk of consolidation in the sector.

BHP Billiton, which was widely-rumoured to be planning a bid for Rio Tinto, sank 2.25 percent to 165 rand while Anglo American tripped 1.19 percent lower to 390.25 rand. Coal producer Exxaro fell 1.88 percent to 62.20 rand.

Gold producers also fell. Prices for the precious metal rebounded from lows on Friday but investors remained nervous because of a firm U.S. dollar and after a sharp drop the previous day.

AngloGold Ashanti skidded 1.5 percent to 300.44 rand, Gold Fields dipped 1.36 percent to 120.09 rand and Harmony Gold fell 1.47 percent to 109.10 rand.

Dealers said sentiment had been hit across the board after U.S. stocks posted their steepest fall in two months on Thursday as disappointing retail sales and a widening trade deficit aroused worries about the economy.

"We are basically following Wall Street's lead," said Greg Davie at Anglorand Securities.