Also on 66 are England's Lee Westwood, Peter Mitchell and Paul Eales and the South African John Bland, with a handful of players one shot behind.
Miller's fellow-Scot, Sandy Lyle, shot a 75 and admits he may even change his putting style in an attempt to recapture his form.
Miller, a former ladies' underwear salesman, has never won a European Tour event in 15 years, and on five occasions has had to return to the qualifying school to win back his card. The 43-year-old is currently ranked a lowly 156th in the Order of Merit and admits the princely pounds 11,001 he has earned so far 'hasn't even covered my expenses', although he did collect a second place in a tournament in Nigeria.
'I'm languishing around the 150 mark but there will be no more languishing from now on,' he said, after shooting six birdies and an eagle.
Lyle, who has switched from Mizuno to Cobra clubs this week, shot a three-over- par 75 and says he may soon try a broom-handle putter. 'I'm getting desperate,' he said. 'I've broken 30 putts only twice in the past 20 months I reckon.
'I started off putting orthodox today and then went cack-handed for a while. I can see me using the broom-handle before the Open.'
The Kent golfer Jamie Spence was another toiling in the Paris sunshine. He carded three bogeys in the last four holes for a one-over 73.Reuse content