West Ham said on Tuesday it had recommended a cash offer of 421 pence per share from consortium WH Holding which values the east London club at around 85 million pounds.
The consortium is bankrolled by the billionaire chairman of Icelandic bank Landsbanki, Bjorgolfur Gudmundsson.
After a poor start to the season which has left West Ham fifth from bottom in the English Premier League, media reports have speculated a takeover could spell the end for manger Alan Pardew. But Magnusson gave his backing to the former Crystal Palace player.
"We can now end the uncertainty of recent weeks and move forward into the next phase of development of this great club, with Alan Pardew leading our efforts on the pitch," he said in a statement
WH Holding has received irrevocable undertakings to accept the offer in respect of approximately 83 percent of West Ham shares.
Magnusson is expected step down from his Icelandic FA and Uefa committee posts once the deal goes through.
The takeover of last year's FA Cup finalists follows a swathe of buyouts of British football clubs.
English champions Chelsea, Manchester United, Aston Villa, Fulham and Scottish side Hearts now all have high-profile foreign owners, while Newcastle United is also currently in talks with potential buyers.