The rating was raised to A-, the fourth-lowest investment grade, from BBB, with a stable outlook, the S&P said in a statement from London. That puts Lithuania's rating on par with Poland, Slovenia and Malaysia.
Lithuania is making a second attempt to adopt the euro after a failed bid in 2006, when it became the only candidate rejected by the European Union because inflation topped the bloc's ceiling by 0.1 percentage point. Lithuania's entry in 2015 would put the entire Baltic region in the euro area, after Estonia joined in 2011 and Latvia entered in January.
"Lithuania's external and fiscal performances have exceeded our 2013 expectations, and we forecast continued strong and sustainable economic growth averaging 4 percent over 2014-2017," analysts including Maxim Rybnikov said in the statement.
Lithuania last had its credit rating raised by S&P to A- in January 2008. S&P's rating increase follows a similar move by Fitch Ratings, which raised the outlook on Lithuania's BBB+, the third-lowest investment grade, last week.
"We believe that Lithuania fulfills all quantitative euro-accession criteria and will be invited to join the euro zone in 2015," S&P said.
Euro adoption will improve Lithuania's monetary flexibility as the central bank "has no meaningful flexibility to steer monetary conditions" under its current currency board policy, S&P said.
