Ratings agency Standard & Poor's downgraded Catalonia moved the region deeper into junk bond territory on Friday evening, expressing less confidence than before in the its financial management and economic relationship with the central government in Madrid.

"On March 18, 2016, Standard & Poor's Ratings Services lowered its long-term issuer credit and senior unsecured debt ratings on the Autonomous Community of Catalonia to 'B+' from 'BB-'. The outlook on the long-term issuer credit rating is negative. We affirmed our 'B' short-term issuer credit and issue ratings on the region."

It de...