UPDATE 2-Sainsbury boss staying put as firm outshines Tesco

* H1 underlying profit 373 mln stg vs forecast 371 mln

* H1 total sales 13.4 bln stg, up 4 pct

* Says has increased market share to near 10-year high

* Shares down 2 percent

LONDON, Nov 14 (Reuters) - J Sainsbury's

highly-respected boss rejected rumours he might be about to

leave Britain's No.3 grocer, as strong growth at convenience

stores and online helped it to outshine market leader Tesco

with higher profit.

Earlier this month, the Financial Times newspaper quoted

unidentified friends of Sainsbury's long-serving chief executive

Justin King as saying his dream job would be to run Formula One

motor racing, fuelling speculation he might step down.

"I do understand why, when someone's been in a job for eight

years successfully, people think they'd have on their mind doing

something else, but I'm very happy at Sainsbury's," King told

reporters on Wednesday.

He said he regarded the firm as having by far the best

growth opportunities of Britain's major grocers in the years

ahead, adding: "I see myself playing my part in those."

King was speaking after Sainsbury's beat forecasts with a

5.4 percent increase in first-half profit, helped by 20 percent

sales increases at its online and convenience stores businesses.

Britain's retailers are mostly struggling as disposable

incomes are squeezed by rising prices, subdued wages growth and

government austerity measures.

But online retailers are bucking the trend as time-pressed

shoppers look to pick up bargains. People are also buying more

groceries locally to cut back on waste and high petrol prices.

Tesco, Britain's biggest retailer, is suffering from its

exposure to out-of-town hypermarkets and non-food goods, where

shoppers are cutting back most. Last month, it reported a 12.4

percent fall in first half UK trading profit.

Britain's No.4 grocer Morrisons last week posted a

2.1 percent fall in third-quarter underlying sales, while No.2

Asda will publish third-quarter sales on Thursday.

"Sainsbury's continues to succeed in an increasingly

competitive grocery environment that is characterised by low to

negative volume growth," said analysts at Conlumino.

CHRISTMAS BATTLE

Last week an industry survey said British retail sales

slowed sharply in October, while earlier this month electrical

retailer Comet collapsed into administration, threatening 6,600

jobs.

King said finance minister George Osborne's Dec. 5 autumn

statement should focus on job creation and on making employment

as affordable as possible for companies. "Employment is by far

the most powerful force for good in our economy," he said.

Sainsbury's shares are up 14 percent over the last year,

partly buoyed by the return of speculation regarding a possible

renewed bid attempt from its 26-percent Qatari shareholder.

But the stock was down 2 percent at 340.3 pence by 1120 GMT,

as analysts highlighted a very promotional, and potentially

margin-hurting, market in the run-up to Christmas, noting that

Morrisons on Tuesday launched a 10 percent off discount card.

Sainsbury's made profit before tax and one-off items of 373

million pounds in the 28 weeks to Sept. 29, ahead of analysts'

average forecast of 371 million pounds in a company poll.

First-half sales rose 4 percent to 13.4 billion pounds as

Sainsbury's increased its market share to 16.7 percent, its

highest for nearly a decade. Last month the firm posted

better-than-expected second-quarter sales growth.

Industry data has shown Sainsbury's sustaining market share

gains from rivals into its second half as it also benefits from

the success of its "Brand Match" pricing initiative, its

strength in cheaper own-brand food ranges and the popularity of

some of its non-food ranges, like Tu clothing.

While the operating profit margin was unchanged, profits

were underpinned by 60 million pounds of cost savings.

Sainsbury's is paying an interim dividend of 4.8 pence a

share, up 6.7 percent.