MOSCOW, Oct 15

Following are the main parties and blocs contesting the election. Parties must win five percent of votes to win seats in the Duma from the 50 percent of seats reserved for party lists.

PARTIES AND BLOCS OFFICIALLY REGISTERED BY THE CENTRAL ELECTORAL COMMISSION AND ALLOWED TO CAMPAIGN

FATHERLAND-ALL RUSSIA - Left-leaning centrist coalition, which is leading in opinion polls, made up of Moscow Mayor Yuri Luzhkov's Fatherland Party and the All-Russia bloc led by former Prime Minister Yevgeny Primakov. Also includes the Agrarian party, former allies of the Communists, who split on joining the bloc.

LEADING CANDIDATES - Primakov, Luzhkov and Vladimir Yakovlev, governor of St Petersburg.

PROSPECTS - Likely to do well although other groups, like the new Yedinstvo bloc, will actively court its electorate.

COMMUNIST PARTY - Far left-wing party advocating redirecting economic reforms, including more state protection for industry, slower privatisation and a wide social security net, as well as voluntary rebuilding of the Soviet Union. It has a steady and inflexible election base of about 20 percent of the electorate.

LEADING CANDIDATES - Party leader Gennady Zyuganov, State Duma speaker Gennady Seleznyov and Vasily Starodubtsev, a one-time member of a group of coup plotters who tried to overthrow Mikhail Gorbachev as Soviet president in 1991.

PROSPECTS - Won more than 22 percent of the vote in 1995, more than any other party. The Communists may not do quite as well this time as rivals will be gnawing at their protest electorate, but they will remain a key force.

YABLOKO - Liberal party which promises more reforms, campaigns against corruption and vows to defend the middle class. Its leader, Grigory Yavlinsky, has declined posts in government and is therefore not tainted with blame for unpopular reforms as are most other liberal leaders. He has lured popular former Prime Minister Sergei Stepashin to stand with him in the poll.

LEADING CANDIDATES - Yavlinsky, Stepashin and Vladimir Lukin, a former Russian ambassador to the United States.

PROSPECTS - Came forth in 1995 with 45 seats. Opinion polls predict similar results in 1999.

PARTIES AND BLOCS WAITING TO BE REGISTERED BY THE CENTRAL ELECTORAL COMMISSION TO BE ALLOWED TO CAMPAIGN

UNION OF RIGHT-WING FORCES - Coalition of "young reformers," who held senior positions in the cabinet and whose names are associated by many with hardship suffered during economic reform. Links the New Force movement of former Prime Minister Sergei Kiriyenko and the Right Cause movement of former First Deputy Prime Minister Boris Nemtsov.

LEADING CANDIDATES - Kiriyenko, Nemtsov and Irina Khakamada, a former government official in charge of promoting small and medium business.

PROSPECTS - The group has a large campaign war chest, but its main task will be to clear the five percent barrier. Opinion polls show it is unlikely to achieve that goal unless helped by some ingenious last-minute campaigning.

YEDINSTVO (UNITY) - Newly formed regions-based election bloc with a vague programme, describing its electoral base as "all thinking people." Branded by rivals as a Kremlin creation designed to steal votes from Fatherland-All Russia, hinges on the popularity of its leader, respected Emergencies Minister Sergei Shoigu, and support from a string of governors.

LEADING CANDIDATES - Shoigu, nine-times world wrestling champion Alexander Karelin, former senior police official Alexander Gurov.

PROSPECTS - Opinion poll findings bode well for the one- month-old bloc although it has done little to organise so far. Its success would come at the expense of Fatherland-All Russia.

OUR HOME IS RUSSIA - Centre-right bloc created in 1995 by then Prime Minister Viktor Chernomyrdin with Kremlin blessing to contest parliamentary elections. Chernomyrdin's sacking as prime minister pulled the rug from under the party, previously seen as the "party of power." Forward, Russia!, a small party of former tax collector Boris Fyodorov has joined its bloc.

LEADING CANDIDATES - Chernomyrdin, parliamentary faction leader Vladimir Ryzhkov, Saratov regional governor Dmitry Ayatskov.

PROSPECTS - Won over 60 seats in 1995, the second biggest standing after the Communists. In disarray since Chernomyrdin's sacking and will be lucky to pass the five percent barrier.

LIBERAL DEMOCRATIC PARTY (LDPR) - Ultra-nationalist one-man party of firebrand politician Vladimir Zhirinovsky which enjoyed surprise success in 1993 and came third in 1995. Advocated radical policy changes including state controls of the economy and tough reprisals against criminals, but later became the government's strongest supporter in the Duma. The party's list was thrown out by the Central Electoral Commission which said many candidates had failed to declare their assets. Now planning to register a new list under the name Zhirinovsky Bloc.

PROSPECTS - Zhirinovsky's support hovers around five percent of the electorate and, being a good last-minute campaigner, he stands a fair chance of breaking the barrier.