UK stocks slip on tariff uncertainty; Heathrow power outage disrupts airlines

March 21 (Reuters) - British stocks closed lower on Friday on continued worries about the economic impact of U.S. tariff policy, while a shutdown of Heathrow Airport pressured travel stocks.

The blue-chip FTSE 100 .FTSE was down 0.6%. The mid-cap FTSE 250 index .FTMC declined 0.9%.

Despite the day's losses, the blue-chip index rose 0.3% this week. The mid-cap index snapped four weeks of losses, rising 0.5%.

Meanwhile, Britain's Heathrow said it had begun the process of reopening, after a fire knocked out its power supply and shut Europe's busiest airport for the day.

The shutdown weighed on airline and travel stocks globally, though stocks pared some losses after the reopening announcement.

British Airways owner IAG ICAG.L fell as much as 4.2% and closed 1.9% lower.

The travel and leisure sector .FTNMX405010 fell nearly 2%.

This week's sentiments were primarily influenced by central bank decisions, with policymakers globally flagging concerns driven by U.S. tariff policy.

While the Federal Reserve projected several interest rate cuts this year, Chair Jerome Powell cautioned that Donald Trump's policies tilted the U.S. economy toward slower growth and at least temporarily higher inflation.

The Bank of England held interest rates at 4.5%, but similarly warned against expectations of future cuts due to an uncertain economic outlook.

Trump said that there would be flexibility on tariffs, ahead of the reciprocal duties he is likely to impose in April.

J D Wetherspoon JDW.L tumbled 9.4%, after the pub group's weak interim profit and poor economic outlook.

JD Sports Fashion JD.L dropped 5.1%, following Nike's NKE.N bleak fourth-quarter revenue outlook.

Iron ore pellet producer Ferrexpo FXPO.L fell 10.8% on Ukraine's VAT refund suspension.

John Wood Group WG.L fell 13.1% after Jefferies downgraded the stock to "hold" from "buy".

On the radar for next week is UK inflation data and the government's half-yearly budget update.

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