The 22-year-old, who has four Scotland caps, joins the Turf Moor club for their first Premier League campaign having scored 52 goals 190 appearances at Easter Road.

Fletcher becomes the club's second signing in a day following full-back Tyrone Mears' capture.

Fletcher has agreed a four-year contract with the Clarets, who will pay the Clydesdale Bank Premier League double their previous record fee having shelled out £1.5million for both Martin Paterson and Chris Eagles last year.

The forward was named Scottish Football Writers' Young Player of the Year in 2007-08 and attracted the interest of Celtic earlier this year.

Mears, meanwhile, has signed for around £500,000 after spending time on loan at Marseille last season.

Mears, 26, is looking for a change of luck in the top flight after a shattering experience in the 2007-08 season.

He was part of the Derby side that finished bottom of the table with an all-time low tally of 11 points.

"It was a freak season, something I do not think will happen again. I have blanked it out of my mind," Mears told Clarets World.

"I like to get forward but it was difficult to do that as we never had any of the ball. I hope it is going to be different this time with Burnley.

"I may have had experience in the top flight but I still need to prove I am a Premiership player."

Mears was anxious to return home from France for domestic reasons. He said: "It was not a decision which was the best club, more about where I was going to be happy in terms of being with my family.

"Marseille is a great club. If it was a different situation I would have signed there.

"But I needed to come back to England and Burnley have given me that chance in the Premier League."