Derby County have pipped Cardiff City to Porter's signature
Striker Chris Porter has completed his move from Motherwell to Derby County in the English Championship.
Manager Nigel Clough pipped Cardiff City to make the striker his first Rams signing, after both clubs tabled similar bids of around £400,000.
"I really enjoyed my time in Scotland and it was a difficult decision to leave Motherwell," Porter told Motherwell News.
"I want to thank to everyone at the club and in particular the supporters."
Porter was Motherwell's top scorer with nine goals this season, but his contract was due to finish in the summer.
Since arriving in Scotland in July 2007, Porter was the subject of much interest, including a £200,000 offer from Huddersfield, while Hearts, Sheffield United and Nottingham Forest were also linked with the player.
"I would also like to thank Mark McGhee, Scott Leitch and all the lads in the changing room," Porter continued.
"I've made some great friends at Motherwell and I'll definitely keep in touch with them.
Porter's new boss Clough told the Derby County website: "It's a terrific capture for us.
"He has a proven track record of scoring goals and has tremendous physical attributes."
The striker watched Derby's home clash with Coventry City on Saturday afternoon.
"I hope he will have a positive impact for us between now and the end of the season," added Clough.
"We have some good competition for places now with the forwards and that can only be good news for us."
Motherwell issued a statement thanking Wigan-born Porter for his 18 months' service, during which he scored 27 times in 67 appearances.
On Thursday, Porter turned back on plans to travel to Wales for signing talks after Derby made their interest known, although the English club were told that they must increase their initial offer for the striker.
Porter will have to wait for his Rams debut, with their next game after this weekend coming on Wednesday when they play Nottingham Forest in an FA Cup fourth-round replay.
The striker, who joined Well after leaving Oldham, is ineligible for the game so could make his bow in next Saturday's Championship match at Plymouth.
Motherwell manager Mark McGhee said the finances would be welcome at the club, although he did not expect to receive any of the transfer fee to spend.
However, the Fir Park club did manage to bring in striker Cillian Sheridan on loan from Celtic until the end of the season.
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