Fitch Ratings has revised Bulgaria's outlook to positive from stable while affirming the sovereign's long-term foreign and local currency issuer default ratings at 'BBB-'.
The issue ratings on Bulgaria's senior unsecured foreign and local currency bonds have also been affirmed at 'BBB-'.
The country ceiling has been affirmed at 'BBB+'.
The short-term foreign and local currency IDRs have been affirmed at 'F3'.
Fitch said Bulgaria's external metrics had improved markedly.
The agency said: "A prolonged and steady deleveraging and positive current account trends helped Bulgaria turn into a small net external creditor to the tune of 1.6% of GDP in 2016.
"This compares with the 0.5% of GDP median net debtor position of its 'BBB' peers, and demonstrates a strong adjustment from a peak net debtor position of 45.2% in 2009."