* Next, Debenhams, New Look trading updates on Tues Jan. 6
* M&S trading statement on Weds Jan. 7
* Sainsbury trading statement on Thurs Jan. 8
By Mark Potter
LONDON, Jan 2 (Reuters) - Trading updates from Marks & Spencer (M&S), Next and Debenhams next week are expected to confirm UK retailers face plunging sales and pressure on profits, with only grocer J. Sainsbury bucking the trend.
Britain's store groups have been slashing prices at unprecedented rates in a bid to lure shoppers who have been curbing spending due to rising unemployment, sliding house prices and fears of a deep recession.
Some have failed to cope, with sweets-to-DVDs chain Woolworths, furniture group MFI and children's wear specialist Adams among those to fall into administration, a form of creditor protection, in recent weeks.
M&S's third-quarter trading update for the three months ending December, due on Wednesday, is likely to attract the most attention, with Chairman Stuart Rose already under pressure from a big profit warning in July, bodged management changes and self-confessed mistakes at the group's upmarket food business.
Analysts expect Britain's biggest clothing retailer to report a drop in sales at UK stores open at least a year of between 5.5 and 9.6 percent, according to a company poll of nine analysts, after a second-quarter fall of 6.1 percent.
A decline of more than 6.3 percent would be the worst quarterly performance since 1999.
Like-for-like general merchandise sales, spanning clothing and homewares, are expected to fall by 6 to 10 percent, while food sales on the same basis are seen down 5 to 10.5 percent.
M&S, which is entering its 125th year and serves more than 21 million Britons a week from over 600 stores, reassured investors in October by saying it had no plans to cut its dividend and announcing plans to reduce capital spending.
But some analysts think trading has deteriorated to the extent the dividend, and profits, will be under pressure.
"We believe the trading statement will disappoint, 2009/10 profits will be downgraded and the 2008/9 dividend will inevitably be cut," said Seymour Pierce's Freddie George.
"The debt covenants are now becoming an issue," he added.
Profit forecasts for M&S for the year to March 2009 have tumbled from over 1 billion pounds ($1.44 billion) a year ago to a current average of 618 million pounds, according to Reuters Estimates.
The average forecast for 2009-10 is 468 million pounds.
UBS, Deutsche Bank, ING and Pali International are among the brokers to have cut estimates in recent weeks.
M&S shares have dropped over two thirds in value over the past 20 months and underperformed the DJ Stoxx European retail Index by 50 percent last year.
NEXT, DEBENHAMS, SAINSBURY
Updates from fashion chain Next and department stores group Debenhams on Tuesday will allow investors to compare different strategies in the run-up to Christmas.
Debenhams, Britain's second-biggest department stores chain by sales behind John Lewis, discounted heavily, while Next, Britain's second-largest clothing retailer by sales behind M&S, held back in a bid to protect profit margins.
Next, which runs more than 480 shops as well as a home shopping business, reported in November a 4.4 percent drop in sales at 334 stores unaffected by new openings for the 14 weeks to Nov. 1, towards the top end of its forecast for a second-half decline of between 4 and 7 percent.
Some analysts think the group may now miss that target, with forecasts for the 21 weeks to Dec. 24 ranging from a decline of 6 percent to a fall of 8 percent, according to three brokerages.
Another poll of three analysts shows Debenhams expected to report a fall in like-for-like sales of between 3 and 5 percent for the 18 weeks to Jan. 3.
Privately-owned fashion chain New Look and homewares group Dunelm will also issue trading statements on Tuesday.
The one bright spot next week is likely to be a third-quarter update from J. Sainsbury, Britain's third-biggest supermarket group, on Thursday.
While there is currently no consensus forecast, recent data from market researchers TNS and Nielsen suggest the group has continued to grow sales and hold onto market share.
Sainsbury, which runs over 500 supermarkets and more than 275 convenience stores, reported a 4.3 percent rise in second-quarter like-for-like sales, excluding fuel.