Complex sentence: In 1989--1990 it took part to the process of integration of the Northern regionalist parties, ahead of regional elections, and, finally, in February 1991, it was merged into Lega Nord, taking the current name.
Split into simpler sentences: In 1989--1990 it took part to the process of integration of the Northern regionalist parties, ahead of regional elections. In February 1991 PA was merged into Lega Nord, taking the current name.