AOL and Time Warner stocks slipped over the holiday period as investors tried to limit tax losses and the two would-be partners were left waiting for approval for their mega-merger from US regulators.

The Federal Communications Commission, the final regulatory hurdle to creating the world's biggest entertainment concern, failed to give the companies a greenlight in the run-up to the New Year. While approval is still expected, AOL and Time Warner may now have to wait beyond January to close the merger.

AOL shares fell to $34.8, down 1.3%, last Friday, the year's final trading day. At one point stocks slumped to $32.9, their lowest point since December1999.

Time Warner shares slipped 2.5% to $52.2, hitting $49.7 at their lowest point. The fall marked a record low for Time Warner stock since November 1999.

Analysts argued that the fall was due to tax-loss selling rather than any fears that the merger would not go ahead. Investors are currently expected to sell stocks that lose ground in order to offset capitol gains.