By Yoruk Bahceli and Samuel Indyk

June 28 (Reuters) - French President Emmanuel Macron's

shock decision to call a snap election, which polls suggest the

far right could win, has rocked financial markets, exacerbating

fiscal sustainability concerns in the euro zone's second-largest

economy.

Markets have stabilised since the June 9 announcement but

are far from recovering.

Polls put Marine Le Pen's National Rally first, but short of

an absolute majority, with investors on edge ahead of two rounds

of voting on June 30 and July 7. They weigh up the RN's fiscal

reassurances against the risk of a spending splurge by a

left-wing alliance, which polls second.

Here are five key questions for markets:

1/ Is there more pain ahead for French bonds?

The risk premium, or spread, demanded by holders of French

debt over Germany's has jumped to around 80 basis points,

nearing levels last seen during the euro zone debt crisis in the

previous decade.

It has now settled but remains over 25 bps above the levels

before Macron's election call. Bond markets reflect expectations

of a "hung parliament, where no single party will be able to get

too many policies through," said Royal London Asset Management

portfolio manager Gareth Hill.

Were markets to stay around current levels, it would cost

France an additional by 800 million euros ($857.92 million) in

the first year, 4-5 billion in the fifth and 9-10 billion by the

10th, its finance ministry estimates.

An absolute majority for the far-right or the left, which

would allow them to implement more of their spending programmes,

could push spreads even higher. Encouraged by RN comments on

fiscal sustainability, many analysts see a left majority as a

worse outcome for markets.

Whether Macron resigns may be key. Citi reckons the

far-right or left implementing most of their programmes without

Macron would raise France's spread to 130-135 bps, compared with

100-105 bps if he stays.

2/ Will turmoil spill into Italy and others?

French turmoil has also pushed spreads higher for the bloc's

"periphery" of highly indebted member states.

Yet the moves have been contained. Italy's

spread rose to the highest since February, but at around 160 bps

is hardly a level that causes concern.

Any further impact should be smaller than in 2017, when Le

Pen's pledges to leave the euro and the European Union she has

since abandoned shook the bloc's bonds broadly.

"Given the lack of anti-euro rhetoric, contagion to the

periphery ought to be limited," said Peter Goves, head of

developed market debt sovereign research at MFS Investment

Management.

Yet tensions between a new government and the EU could limit

further European integration and "increase the vulnerability of

the periphery to any shock," BofA says.

3/ How could banks fare?

French banks have been among the biggest losers from the

turmoil. The big three - Societe Generale, BNP Paribas

and Credit Agricole - are down 9%-15% since

Macron's announcement.

"French banks have a large amount of debt and they will

suffer if you see higher credit costs or a sharp increase in

borrowing at the government level," said Nathan Sweeney, chief

investment officer of multi-asset at Marlborough.

"If it's Le Pen, does that mean windfall taxes or taxes on

dividends? That creates uncertainty for banks," he added.

For now, the reaction has been excessive, said Barclays

equity analyst Sam Moran-Smyth, given the limited earnings risk

facing French banks at this stage, and valuations that were

already depressed before the election announcement.

But Societe Generale and Credit Agricole are more at risk

than BNP, given BNP's more diversified geographic and business

mix, Moran-Smyth said.

4/ What about other French stocks?

The broader French market has not been spared - the

blue-chip CAC 40 index is down over 5% since Macron

dissolved parliament.

Infrastructure and utility stocks suffered the most, with

Vinci, Eiffage and Engie down

10%-13% since the election call.

The RN has previously pledged to nationalise highways, but

left such plans out of its new programme. In the current

campaign, it has laid out plans that disregard EU rules on power

prices and to ramp up taxation on power producers' exceptional

profits.

Corporate debt has also taken a beating. French

companies are the biggest group in European corporate bond

markets, making up 23% of ICE BofA's index, according

to Janus Henderson.

5/ Is it lose-lose for the euro?

The euro is down 1% against the dollar since the

election announcement and hit an eight-week low on Wednesday.

A hung parliament would be negative for the euro, but the

worst outcome would be an RN majority, said MUFG senior currency

economist Lee Hardman.

"In that scenario, we would see euro-dollar breaking to a

new lower range, we think towards parity."

Further political uncertainty would benefit the Swiss franc

the most, given its role as a regional safe haven, Hardman said.

($1 = 0.9325 euros)