Britain's biggest department store chain John Lewis said last week's sales growth was held back by hot weather, which meant it lost shoppers to alternative outdoor pursuits, as well as tough comparative numbers last year.

It was a week of unseasonably hot weather right across the country, even in Scotland where record temperatures matched those in the Mediterranean, Barry Matheson, director, retail services, said on Friday.

Inevitably that brought opportunities and challenges across our assortments and shops. We were also up against last year's launch of the (Apple ) iPad 2.

The employee-owned retailer said department store sales rose 6.5 percent to 57.9 million pounds in the week to March 24.

That was a significant slowdown on the previous week's Mother's Day assisted stellar growth of 20.9 percent.

John Lewis highlighted the performance of its electicals and home technology division, where sales increased 22.3 percent, driven by demand for the new iPad and televisions ahead of next month's digital switchover in London. However, sales in the home category fell 0.3 percent.

The firm has been outperforming the wider retail market as its more affluent customers have been less impacted by the economic downturn.

The latest John Lewis sales are respectable and the overall performance for March has been strong, which provides some welcome and much-needed encouraging news on the consumer front, said IHS Global Insight chief economist Howard Archer.

However, it must be borne in mind that while John Lewis has often been seen as a bellwether for the state of consumer spending, it has been very much an out-performer in recent times.

Many UK retailers are still struggling as consumers grapple with inflation, muted wage growth and government austerity measures, and worry about job security and a stagnant housing market.

Separately on Friday a report said UK consumer confidence unexpectedly fell to a three-month low in March as Britons grew increasingly worried about the outlook for their finances and for the economy as a whole, denting hopes of a consumer-fuelled recovery.

John Lewis also owns upmarket grocery chain Waitrose. Here, week to March 24 sales rose 5.9 percent to 106.1 million pounds.

Conversely it benefited from the hot weather with sales of barbecue lines up 461 percent. ($1 = 0.6285 British pounds)

(Reporting by James Davey; Editing by Matt Scuffham)