PARIS—Fitch Ratings has lowered credit ratings for several leading French banks, days after downgrading the country's credit status as it struggles with huge debt.

The ratings agency on Wednesday cut the main credit score for banks Credit Agricole, Societe Generale, Groupe BPCE and Dexia from A+ to A. It also lowered ratings for local and regional French governments.

The decision was linked to its downgrade of France's default ratings from the top-tier AAA to AA+ last week. That means the government's "ability to support French banks has decreased slightly," Fitch said in a statement.

France's Socialist government unveiled a modest stimulus plan last week and new measures Wednesday meant to simplify a bureaucracy-heavy, highly taxed economy.

Europe's No. 2 economy is back in recession and facing weak growth prospects.