"I want Owen to stay and I'm certain he will stay," said Gartside. "We've formed a good working relationship and I respect the way he works.
"He's been very unlucky this year. He's a young manager, he's learned a lot and we've invested in that."
Coyle, 45, is a former Bolton player and
took over from Gary Megson as manager
at the Reebok Stadium in January 2010, guiding Wanderers to a final position of 14th in both of his first two seasons in charge.
But with a number of serious injuries to contend with this term, Bolton could not escape the drop to the Championship.
"The experiences we've all had this year have been unique and unprecedented," continued Gartside. "These are not excuses, they are reasons.
"During the season, we've had 15 trauma injuries, including four broken legs. I've been on the board for nearly 30 years and I've never seen a season where we've had such a horrendous injury list.
Owen Coyle's Bolton record
Appointed manager in January 2010
Managed Bolton for 115 matches
Wanderers have won 39, drawn 22 and lost 54
In 2009-10 Bolton finished 14th on 39 points
In 2010-11 Bolton finished 14th on 46 points
In 2011-12 Bolton finished 18th on 36 points and were relegated
"We've never moaned about it and we've had to deal with it."
A number of first-team players, including club captain Kevin Davies, are out of contract in the summer.
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