JOHANNESBURG/LONDON - Nigeria's new president, in office for less than a month, is pushing to put Africa's largest economy on a reform track that investors have eyed for decades, fuelling excitement that money could flow to a nation that many had deemed uninvestible.

President Bola Tinubu's bold actions, including removing restrictions on the naira currency that allowed it to hit a record 790 to the dollar and subsidy removals that tripled petrol prices, could take stress off the battered finances of Africa's largest economy.

But investors, burned by previous reforms that ultimately proved hollow, say it will take time to build trust and listed myriad questions over the final shape of the economy.

"The reaction is one of, 'finally'," said Tunde Ajileye, a partner at Lagos-based SBM Intelligence. "If this stays, then it would mean that (Tinubu) had been able to remove the two subsidies that have crippled Nigeria fiscally and monetarily for the last decade."

Tinubu is from the same party as predecessor Muhammadu Buhari, dubbed "Baba Go-slow" for his pottering pace - taking six months to appoint cabinet members.

By contrast, Tinubu lifted fuel price caps days after taking office on May 29, suspended controversial Central Bank chief Godwin Emefiele some 10 days later and on Wednesday removed FX restrictions.

The tangle of multiple exchange rates for everything from international school fees to food imports created foreign currency shortages and hobbled investment due to issues getting money out.

"Just the fact that you have seen quite a bit of movement in a relatively short space of time has gotten a lot of people in the market excited," said Goldman Sachs economist Andrew Matheny. Nigeria's international dollar bonds and the country's stock market have been boosted by the speedy reforms.

BACKLOG, AND BURNED BEFORE

Investors, though, remained wary, citing years of damaging currency controls; Goldman Sachs pegged the backlog of FX demand at a staggering $12 billion.

"We are still to see whether this will allow the FX backlog to clear, where the new market rate will stabilise, whether this will catalyse inflows into the country and ... that there will be no issues pulling money out of the country," said John Mumo, a partner at Blakeney, an Africa-focused equities fund management firm.

Joe Delvaux, a portfolio manager at Europe's largest asset manager Amundi, said it could take months or more to lure longer-term cash.

"Ultimately, you also have to keep in mind that the biggest provider of FX will still be the CBN," Delvaux said.

"We need to see that the system works."

Tinubu will also have to tackle the perennial corruption that has hobbled the country for decades. Nigeria is ranked 150 out of 180 in

Transparency International's 2022 corruption perceptions index - and has been on a downward trend since 2016.

Investors also worry about low tax receipts and falling oil output - structural reforms that will take far longer to sort. Some are also hoping to see a more orthodox interest rate policy. Inflation hit a near 20-year high of 22.41% in May and a weakening naira will amplify price pressures. Meanwhile interest rates, which Tinubu has said he would like to see fall, were hiked by 50 bps last month to 18.5%.

"Investors will need to see positive real rates and evidence that they will be able to repatriate their earnings before local currency debt is back in play," said Patrick Curran, senior economist at Tellimer.

(Reporting by Rachel Savage and Libby George, Editing by Karin Strohecker and Nick Macfie)