By Alan Baldwin

AUSTIN, Texas (Reuters) - Formula One's commercial supremo Bernie Ecclestone has spoken out in support of Ron Dennis amid continuing speculation that shareholders are seeking to replace the McLaren boss.

"If I was going to run a team I’d like to have Ron with me," the Briton told Reuters at the U.S. Grand Prix, which Dennis attended 50 years on from his first involvement at a race weekend.

"I think he does a good job. Anyone that chucks him out is stupid. He’s dedicated. I think we ought to try and support him so they don’t get rid of him," added Ecclestone, who will turn 86 in Mexico next Sunday.

"It would be a shame to see him go. He’s one of the good old timers."

Britain's autosport.com website said in an unsourced report last week that Dennis, 69, would be leaving as McLaren chairman and chief executive at the end of the year when his contract expired.

A McLaren spokesman said in response that Dennis, who attended his first Formula One race as a Cooper mechanic in Mexico in 1966, had stated "categorically" that he is not stepping down.

"Moreover, he remains contracted as chairman and chief executive officer of McLaren Technology Group and he retains a 25 percent shareholding -- exactly equal to that of (Saudi-born business partner) Mansour Ojjeh."

'INSPIRATIONAL CHAIRMAN'

Mahmood al-Kooheji, CEO of Bahrain's sovereign wealth fund Mumtalakat, which owns the other 50 percent, told Reuters they had "great admiration" for Dennis.

"He's a colleague, an inspirational chairman who is behind all the ideas," he said. "Whatever he decides, we will support his decision. I hope he continues and I will try to make him stay."

However, former McLaren driver turned television commentator Martin Brundle said he expected Dennis to leave.

"There seems to have been some friction and there seems to be a new direction they want to go in," he told Sky Sports television.

"I don't know who they've got in mind and (in) which elements of McLaren they will make changes, and whether they will restructure. We'll have to wait and see."

Dennis, who has been involved with McLaren since 1980, stood down as team boss in 2009 but returned as group chief executive in January 2014.

McLaren changed their name in 2014 to McLaren Technology Group, incorporating the sportscar company and applied technologies as well as the F1 team.

Mumtalakat agreed that same year to sell some shares to Dennis but there has been no confirmation of that happening.

McLaren have not won since 2012 and struggled last year at the start of a new partnership with Honda. They have improved since and recorded their fourth double points finish of the season on Sunday.

(Additional reporting by Stanley Carvalho in Abu Dhabi; Editing by Ian Ransom/Peter Rutherford)