LONDON - Marks & Spencer (MKS.L) is expected to report lower first-half sales and profits next week, ratcheting up the pressure on its chief executive at a time when the retailer's shares are on the rise thanks to bid speculation.

Although analysts expect second-quarter sales at Britain's biggest clothing retailer to show an improvement on the first quarter, they also anticipate the 128-year-old firm will post an 11 percent fall in first-half profit.

That will not look good when compared to recent relatively positive updates from rivals Next (NXT.L), Debenhams (DEB.L) and ASOS (ASOS.L).

Marc Bolland, CEO since May 2010, has had a tough 2012.

In May he slashed M&S' three-year sales growth target, blaming the recession, and in July he shook up his general merchandise management team after the group reported its biggest quarterly sales drop for 3-1/2 years, blaming wet summer weather and stock management issues that left stores short of bestselling womenswear lines.

In September Bolland told Reuters he had fixed these problems and insisted he was not feeling the heat from investors despite renewed talk of a possible bid for the group.

Shares in the company have risen 18 percent over the last three months, buoyed by persistent speculation regarding a possible offer from private equity or a sovereign wealth fund.

Some analysts have been critical of the investment required to deliver Bolland's strategy of embracing multi-channel retailing - connecting with customers via many different types of channels including online - particularly in non-food, and selective overseas expansion.

At home, M&S sells clothes, footwear, homewares and foods from 730 stores to 21 million Britons a week, and has 390 stores in 44 countries.

"The promotional strategy in general merchandise is brand-damaging, in our view," said Investec Securities analyst Bethany Hocking, referring in particular to what she sees as excessive promotions in clothing.

"We don't see acceptable returns on 2.4 billion pounds ($3.9 billion) of capex FY13-15 and we expect bid spec, which has driven the shares higher, to die down."

Analysts expect M&S to post on Tuesday a pretax profit before one off items of 250-305 million pounds ($402-491 million) for the six months to September 29, with a consensus of 280 million pounds, according to a company poll of 10 analysts, down from 315 million pounds in the same period last year.

General merchandise sales from its British stores open over a year are tipped to have fallen 2.5 percent in the second quarter, having slumped 6.8 percent in the first quarter.

Food sales are seen 1.5 percent higher, accelerating from growth of 0.6 percent in the previous quarter.

Key will be M&S' outlook for Christmas, the busiest trading period of the year. The firm will be looking for an improvement on Christmas 2011 when unusually mild weather hit clothing sales.

British retailers are generally finding the going tough as consumers hold back spending in the face of inflation, meagre wage increases and government austerity measures.

British retail sales picked up more than forecast in October, a survey showed on Tuesday. However, one published on Wednesday said UK consumer confidence fell to its lowest in six months in October, highlighting the fragility of any recovery from recession.

Next week will shine more light on the strength of consumer spending.

On Thursday Britain's No. 4 grocer Wm Morrison Supermarkets (MRW.L) is expected to report that sales at stores open at least a year, excluding petrol, fell 2 percent in its third quarter, according to a company poll of analysts, having fallen 0.9 percent in the first half.

On Wednesday British luxury fashion brand Burberry (BRBY.L), which issued a shock profit warning in September, is expected to post a first-half adjusted pretax profit of 167 million pounds, according to a company compiled consensus.

This compares to the 162 million pounds adjusted pretax profit it posted in the same period a year ago.

Primark-owner Associated British Foods (ABF.L) will post its year-end results on Tuesday, with SuperGroup (SGP.L), the company behind the Superdry fashion brand, publishing an update on second-quarter trading on Thursday.

($1 = 0.6218 British pounds)