The union originally rejected a realignment proposal, but agreed to a slightly altered version.
"After discussions with the executive board, the NHLPA has given consent to realignment, to be re-evaluated following the 2014-15 season," Fehr said in a statement.
The plan must still be approved by the NHL's board of governors, which is expected to be a formality.
NHL teams would continue to be split into Western and Eastern conferences, but instead of six divisions there will now be four -- the Atlantic, Central, Midwest and Pacific.
Carolina, Columbus, New Jersey, Pittsburgh, Philadelphia, Washington and both the Islanders and Rangers will fall into the Atlantic Division. The Central Division will be made up of Boston, Buffalo, Detroit, Montreal, Ottawa, Toronto, Florida and Tampa Bay.
Those competing in the Midwest Division will be Chicago, Colorado, Dallas, Minnesota, Nashville, St. Louis and Winnipeg while the Pacific Division will consist of Anaheim, Calgary, Edmonton, Vancouver, San Jose, Los Angeles and Phoenix.
Qualifying for the playoffs would be changed so that the top three teams from each division would make it to the postseason along with the teams with the next two best records from each conference.