The two main parties wanting Spain's Catalonia region to break away from the rest of the country say they will run joint candidates in regional elections scheduled for September to avoid splitting the pro-independence vote, strengthening their chances of winning power.

Convergence and Union, the party which has governed the powerful northeastern region for 28 of the almost 40 years since the death of dictator Gen. Francisco Franco, and the Republican Left announced the agreement Wednesday.

The two parties say they regard the elections for the Catalan parliament as a vote on independence and will unilaterally leave Spain if they obtain a majority of seats.

Parties opposing independence have announced no plans to run on a common platform. They say the elections aren't an independence referendum.