The benchmark FTSE 100 share index ended the week down 37.6 points at 7,312.72 at the close of trading.
The pound dipped after figures showed a drop in UK households' disposable income. The Office for National Statistics data also showed that the savings ratio had fallen to a record low.
The pound ended at $1.2996. Against the euro it was unchanged at 1.13685 euros.
Shares in United Utilities ended the session down 3.45% after Credit Suisse cut its rating on the stock to "underperform" from "outperform".
Outside the FTSE 100, shares in Game Digital dived nearly 35%% after the video games retailer issued a profit warning.
The company said trading had been affected by lower than expected supplies of the Nintendo Switch console.
The UK's stock market slipped as the pound edged back below the $1.30 level.