JOHANNESBURG (Reuters) - South Africa's credit rating could get downgraded deeper into junk status if political uncertainty triggered by the recent firing of the finance minister stalls reforms needed to grow the economy, an executive from S&P Global Ratings said on Wednesday. "There are risks that potential growth outcomes could be weakened, especially with uncertainty that's been brought along in a year where you may not get strong decisions for strong reform programs," said Gardner Rusike, the associate director and lead analyst for South Africa at S&P. S&P downgraded South Africa's sovereign credit rating to BB+ with a negative outlook from BBB- grade on April 3, saying the firing of its internationally respected finance minister Pravin Gordhan posed a major risk to fiscal policy. The new Finance Minister Malusi Gigaba has said Treasury is committed to fiscal consolidation plans outlined in the 2017 budget after S&P and Fitch downgraded the country to sub-investment grade. Rusike said political jostling ahead of the ruling African National Congress's conference at year-end, where the party will elect leaders to contest general elections in 2019, was likely to distract government from implementing economic reforms. "You are probably looking at a much longer time line when you are talking about the path of economic growth that can help to stabilise debt," Rusike said. "We've had three downgrades over the last four or five years which means that the credit story for South Africa has been deteriorating." The country's net debt currently sits just below 50 percent of gross domestic product, at around 2.2 trillion rand ($165 billion), and in recent budgets the treasury has said the cost of servicing that debt has been one of the fastest growing items. ($1 = 13.3209 rand) (Reporting by Mfuneko Toyana; Editing by James Macharia and Toby Chopra)