ESSENDON has secured its first deal under the AFLW's new priority signing period (PSP) rules, locking away an agreement to poach highly rated North Melbourne defender Brooke Brown.

It's understood Brown informed Kangaroos officials of her decision to depart for Tullamarine on Tuesday, barely 24 hours before expansion clubs hit their PSP deadline at 2pm AEDT Wednesday.

Brown, who turns 26 next month, emerged as one of the League's best rebounding defenders and ball-users across half-back throughout a career-best season seven where she averaged 13.5 disposals and 4.1 marks per game.

SIGNED, SEALED, DELIVERED All the PSP moves as they happen

Essendon, who can sign two players under PSP rules, had yet to dip into the market but had been aggressively targeting additional defensive depth across the competition in recent days.

They had previously been the only expansion club yet to sign players from the PSP pool, with Sydney, Hawthorn and Port Adelaide having already taken advantage of the new AFLW rules to secure landmark signings.

Sydney has filled two of its five spots thanks to deals for Chloe Molloy and Lucy McEvoy from Collingwood and Carlton respectively, Hawthorn has added Brisbane premiership duo Emily Bates and Greta Bodey, while Port Adelaide has signed Ash Woodland from crosstown rivals Adelaide as well as Fremantle defender Janelle Cuthbertson.

The Swans are still able to sign three more players before Wednesday's PSP deadline, while each of the Bombers, Power and Hawks can sign one more player without having to negotiate a trade.

Brown, who was recruited from Tasmania, has played 24 games for North Melbourne.