FACTBOX - Main sticking points of EU reform treaty

(Reuters) - European Union leaders meet in Lisbon on Thursday and Friday to approve a new treaty overhauling the enlarged 27-nataion bloc's institutions to make them stronger, more efficient, democratic and transparent.

Several snags remains, involving Poland, Italy, Austria and Bulgaria, but current EU president Portugal believes they can be resolved in negotiations.

Following are the main sticking points:

POLAND

Under the conservative Eurosceptical Kaczynski twins, Poland has fought for medium-sized countries to have more voting power.

Warsaw's main demand is to include in the treaty, or as a protocol, a provision allowing groups of countries that are just short of a blocking minority to delay a decision for a "reasonable time" -- in practice several months.

The provision, known as the Ioannina Compromise after a Greek town where it was agreed in 1994, has never been used and most EU members want to keep it as a political declaration, which can be amended more easily.

Diplomats say a possible way out would be a "weakened" protocol, which could be scrapped or amended without the normal, cumbersome procedure for changing a treaty.

Another possibility is a "reinforced" declaration, which would be require unanimity of member states to be scrapped.