SCENARIOS-Greek snap poll may lead to coalition, new election

ATHENS, Sept 4 (Reuters) - Greek Prime Minister Costas Karamanlis called snap elections for Oct. 4, taking a gamble as he lags in polls and no party is seen winning outright, raising the prospect of a long period of uncertainty. Here are scenarios of how the situation could develop and the political and financial risks involved:

ONE PARTY WINS OUTRIGHT

Polls so far show this is unlikely, though most Greeks would like such an outcome, as would the financial markets.

NO CLEAR WINNER

This is the most likely result. The socialist PASOK party, which had a lead of about 6 percentage points in polls published before the snap election was announced, is seen beating the ruling conservative New Democracy party but without enough votes to form a government.

Should that happen, there would be another election or, much less likely, a coalition government would be formed.

EFFECT ON MARKETS, ECONOMY

Most analysts say an inconclusive vote would increase uncertainty in debt-ridden Greece, which risks falling into recession this year and needs a strong government to push through long-delayed reforms.

Greek stock prices .ATG fell on Thursday on fears there would be no clear election winner. For the same reason, the premium investors demand to hold 10-year Greek bonds rather than benchmark German Bunds rose to a six-week high on Friday.

ANOTHER ELECTION

This is the most likely outcome if PASOK wins but cannot govern on its own. It has said it would, in this case, ask for the new election to be held under a new electoral law that gives the winning party an increased first-party bonus, enabling it to win an absolute majority of seats more easily.

This would extend the electoral period by at least 30 days.

COALITION POSSIBILITIES

PASOK is open to cooperation with other leftist parties but the communist KKE and the Left Coalition have ruled this out.

Should New Democracy make a surprise comeback, the far-right LAOS is eager to be in government. New Democracy has so far refused its support but may change its mind if many of its disgruntled voters turn to LAOS. The outgoing government has already toughened migration policies since LAOS's success in EU elections in June.

If none of the three leading parties can form a coalition, the president dissolves parliament, calls new elections and asks a senior court official to form a caretaker government.

BLOCKING TACTICS?

The loser could trigger another parliamentary election in March by blocking the election of the president. Analysts see this as unlikely as no party would gain from dragging Greece through a prolonged crisis.

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For an analysis [ID:nL2532370] For factboxes, click on the following links:

- the issues -- economy, graft [ID:nL3578236]

- the main parties' policies [ID:nLL3491307]

- profiles of Greek PM, opposition leader [ID:nL1191161]

- the outgoing government's woes [ID:nL2163569]