Credit rating agency Fitch has upgraded the credit ratings of Philippines economy to investment grade, a first time achievement for the Southeasat Asian nation, citing its strong balance sheet, resilient economy and effective fiscal management.

The country's long-term local-currency issuer default rating (IDR) has been upgraded to BBB from BBB- and long-term foreign-currency IDR has been upgraded to BBB- from BB+. The outlook on the ratings is stable.

Fitch said in a statement that Philippines' sovereign external balance sheet is strong relative to A range peers with a "persistent current account surplus".

Despite a weak global economic backdrop, the Philippine economy expanded by 6.6 percent in 2012, with a 6.8 percent growth in the fourth quarter. Driven by strong domestic demand, the country's growth has been stronger and less volatile that its BBB peers, according to Fitch.

Government's debt/GDP ratio also supports the new ratings, Fitch noted. The ratio was strengthened by the country's economic growth and moderate budget deficits.

President Benigno Acquino who took office in 2010 has introduced a series of measures to reduce corruption, curb the budget deficit and increase the government spending, thereby boosting the economic growth despite adverse global economic conditions. The government currently hopes to achieve economic growth of 8.5 percent by 2016.

Fitch added that the country's inflation rate is in line with its BBB peers over the past five years. The Philippines' central bank has been proactive is using macro measures, the agency said. The central bank also had cut interest rates four times in 2012 in order to boost sustained growth.

However, the country's governance standards, average income and fiscal revenue generation are still below its peer levels, Fitch noted.

Economists expect the Philippines to top economic growth among nations in the Southeast Asia region with increased spending in healthcare, education and social programs along with opening the economy for foreign investors.

Fitch expects the country's gross domestic product to grow 5.5 percent in 2013. The World Bank had predicted the Southeast Asian nation to grow by 6.2 percent in 2013 and 6.4 percent next year.