Under the draft agreement, the new party will be called the Croatian People's Party - Liberal Democrats, while its acronym will remain HNS.
HNS president Vesna Pusic will be the new party's leader, while Libra leader Jozo Rados will be her deputy. Three members of Libra's Presidency will be appointed to the HNS Presidency.
The new party will hold its unification assembly in Zagreb on February 6.
The HNS Central Committee also endorsed a Declaration on Europe which the HNS will send to Parliament.