MILAN, Italy (AP) _ Hundreds of international transport trucks began backing up at Italy's border posts Friday as truckers rushed to avoid a strike by Italian customs officers.

Commercial traffic is expected to halt at Italy's borders with France, Switzerland, Austria and Yugoslavia on Monday during a nationwide strike by 8,000 customs officers.

Traffic police reported that more than 1,000 trucks lined up at the Italian-Yugoslav border point of Fernetti, near Trieste.

Trucks were also backed up on the Austrian side of the Brenner pass and at some Italian-Swiss border points.

Customs officers decided on a full day of strike action to protest the Italian government's failure to reform commercial traffic and customs regulations.

''It's a three-year-old problem, still unsolved,'' said an officer at the Brenner pass. ''Only a few commercial vehicles will get through Monday.''