Curbishley took over at Upton Park in December 2006
West Ham's vice chairman has rejected Alan Curbishley's claim that the club's transfer policy represented a "breach of trust and confidence".
Curbishley stepped down as Hammers boss on Wednesday, complaining that transfer decisions had been made without him.
"We agreed a transfer budget and the way forward at an April board meeting," Asgeir Fridgeirsson told BBC Sport.
"Alan agreed with the plans, but was then reluctant to reach all the difficult decisions about the squad."
The final straw for Curbishley was the transfer deadline day sale of George McCartney to Sunderland.
Only a few days earlier, the 50-year-old had vowed not to sell any more players following the summer departures of John Pantsil, Bobby Zamora, Richard Wright and Anton Ferdinand.
We began to feel we were vulnerable in having a structure with one manager who runs all football matters
Asgeir Fridgeirsson West Ham vice chairman
But Fridgeirsson, who is owner Bjorgolfur Gudmundsson's right-hand man, said Curbishley was fully aware of the need to trim the club's wage bill.
"If Alan had made this claim in April, when discussing our budget and plans for the forthcoming season, he might have a legitimate complaint," added Fridgeirsson.
"But he went to all the board meetings and was a dominant voice."
Fridgeirsson also defended the management structure at the club, under which chief executive Scott Duxbury and technical director Gianluca Nani take a lead in transfer policy.
"About a year ago, we began to feel we were vulnerable in having a structure with one manager who runs all football matters," he said.
"If the manager leaves, where does it leave you? So we decided to build an infrastructure and philosophy for the club, which would provide continuity.
"We want a strong English club with English players, with its roots in the academy."
Owner Bjorgolfur Gudmundsson has been eager to build a more "sustainable" club
The Hammers have also invested heavily in their medical and training facilities in the last year.
Work on a new training ground is planned to start early next summer and several new appointments have been made to the medical department.
"We have £100m in assets in terms of players and a £55m-plus salary bill, so it's crucial to look after the players and get the best out of them," said the vice chairman.
"We have been gathering experience from other clubs on the continent in this regard. We have recruited an osteopath from AC Milan, who has done excellent work with players such as Craig Bellamy.
"If you look at a club like Milan, the medical department belongs to the club. A manager might be tempted to take a short-term view to medical matters, choosing to field an injured player in a crucial match.
"But at AC Milan, the same doctor has been looking after Paolo Maldini's knee for the last 20 years."
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