JOHANNESBURG (Reuters) -The South African rand strengthened on Friday, ahead of a general election and an interest rate decision next week.

At 1507 GMT, the rand traded at 18.4250 against the dollar, up 0.31% from its previous close.

The dollar index was around 0.33% weaker against a basket of global currencies.

South Africans will on May 29 vote in an election where polls suggest the ruling African National Congress could lose its legislative majority for the first times since coming to power 30 years ago.

"The week ahead does provide the potential for near term volatility as we approach local elections as well as the SARB rates decision and monetary policy statement," said Shaun Murison, senior market analyst at IG.

The South African Reserve Bank (SARB) will deliver an interest rate decision on Thursday, a day after the election.

On the Johannesburg Stock Exchange, the blue-chip Top-40 closed 0.24% higher.

South Africa's benchmark 2030 government bond was weaker, with the yield up 10.5 basis points to 10.535.

(Reporting by Tannur Anders and Bhargav Acharya; Editing by Bate Felix and Josie Kao)