* John Dixon resigns to take on CEO role at unnamed firm
* Food boss Steve Rowe becomes head of general merchandise
* Rowe move may make him favourite to be next group CEO
* Andy Adcock named interim head of food (Adds detail, background, analyst comment, shares)
By James Davey
LONDON, July 16 (Reuters) - John Dixon, the head of Marks &Spencer's non-food division, has quit Britain's biggestclothing retailer to become chief executive of another company,M&S said on Thursday.
The 131-year-old M&S said Dixon, whose purview spansclothing, shoes and homeware, would step down from the M&S boardimmediately and leave the company on a date to be agreed. Hisdestination was not disclosed.
"I now have the opportunity to become a chief executive andhave therefore resigned from this great company," he said.
M&S said that in line with its succession plans, Dixon'srole as the head of the firm's most profitable division will beassumed by Steve Rowe, head of its successful upmarket fooddivision.
Analysts speculated the change puts Rowe, who has been withM&S for more than 26 years, in pole position to succeed groupChief Executive Marc Bolland when he decides to depart.
POISONED CHALICE
But some suggested the change could harm his chances.
"I think the odds have just lengthened. Steve Rowe wouldhave been much better placed if he was still running food ratherthan drinking from the poisoned chalice that is M&S clothing,"said independent retail analyst Nick Bubb.
Rowe himself has made no secret of his desire for the topjob, telling Reuters last year he would like to beCEO.
M&S said Andy Adcock, currently trading director, food,would step up to be director of food, reporting to Bolland on aninterim basis.
Dixon had headed the non-food business since 2012 andpreviously ran the food business for four years.
He was considered to be a candidate to succeed Bolland asCEO, but his star has waned as M&S has struggled to deliver asustained increase in underlying clothing sales.
Earlier this month M&S reported a dip in first-quarterunderlying sales in general merchandise, a setback after areturn to growth for the first time in 15 quarters in theprevious three months.
At the same time the credentials of Rowe for the CEO jobhave been enhanced by 23 straight quarters of underlying salesgrowth in food and an outperformance of the wider grocerymarket.
Laura Wade-Gery, executive director multi-channel, and HelenWeir, the new chief finance officer, are also considered byanalysts and investors to be candidates to succeed Bolland.
However, Bolland, CEO since 2010, said in May he had noplans to depart any time soon, telling reporters he "absolutely"expected to present financial results in May next year.
Shares of M&S closed Thursday at 547 pence, valuing thebusiness at 9 billion pounds ($14 billion).($1 = 0.6407 pounds) (Reporting by James Davey; Editing by Jane Merriman and SteveOrlofsky)