NEW DELHI, Dec 4 (Reuters) - India's Hindu nationalist opposition party emerged as the biggest winner in four key state elections, exit polls forecast on Wednesday, a possible blow to the ruling Congress party ahead of a general election due next year.
India has held elections in Delhi, Madhya Pradesh, Rajasthan and Chhattisgarh states over the past month, as well as in the small state of Mizoram. Counting and results for all the states are due on Sunday.
Despite the gains predicted for the nationalist Bharatiya Janata Party (BJP) it was unable to win a majority of seats in the capital Delhi, the two polls showed. One poll suggested the race was close in Chhattisgarh.
The results are being closely watched by markets as a potential indicator of the mood of voters in the world's biggest democracy before the 2014 general election.
Indian markets have rallied in recent weeks on signs the BJP's business-friendly candidate for prime minister Narendra Modi is gaining popularity.
The Congress party has led the coalition ruling India for two consecutive terms but has tested voters' patience with a string of corruption scandals and a lacklustre economy.
India's fragmented political landscape makes a coalition government the most likely outcome after the next elections.
Opinion and exit polls have a patchy track record in India. Most surveys forecast the wrong outcome in the 2004 general election.
An exit poll by India TV-CVoter predicted the BJP would win Rajasthan from Congress and retain its majority in Madhya Pradesh. In Delhi the BJP will emerge as the biggest party but will not have a majority, the poll forecast, with a new anti-corruption party making a strong showing in third place.
A separate poll by India Today-ORG showed similar results but gave the BJP a majority in Delhi.
In Chhattisgargh, both polls forecast the BJP remaining the strongest party, but Times-CVoter said it would fall short of a majority, with only a three-seat difference between the two parties.
The surveys were carried out on election day with sample sizes ranging from a few hundred to several thousand voters, depending on the size of the states. (Reporting by Frank Jack Daniel; Editing by Mark Heinrich)