Key numbers to watch in Japan July 10 upper house election

TOKYO (Reuters) - Japanese Prime Minister Shinzo Abe's Liberal Democratic Party (LDP), along with its junior coalition partner, the Komeito party, aim to win a combined majority of the 121 seats up for grabs in an upper house election on Sunday. Abe has presented the vote as a referendum on his "Abenomics" stimulus policies of bold monetary easing, flexible fiscal spending and reforms. An election is held every three years for half of the upper house's 242 members, who have six-year terms. Here are some key seat numbers to watch. RULING BLOC NEEDS 46 SEATS TO KEEP MAJORITY The LDP held 116 seats in the upper house before the election, falling short of a majority, but together with the Komeito's 20 seats, the ruling bloc controlled the chamber. If the LDP and Komeito together win 46 seats, they would keep their majority. RULING BLOC NEEDS 61 TO HIT ABE'S TARGET Abe has delayed a sales tax increase by 2-1/2 years, until October 2019, saying he aims to win more than half the seats in contention to gain a mandate for his decision and his economic policies. The LDP and Komeito have 60 lawmakers among the half of the members of the upper chamber whose seats are being contested on Sunday. LDP NEEDS 57 TO WIN SIMPLE MAJORITY ON ITS OWN If the LDP wins 57 seats or more, it would have a majority without the help of coalition partner Komeito, affording Abe a more independent stance in making policy. The LDP had 51 upper chamber seats whose occupants' terms expired. The LDP has not held an upper house majority on its own since 1989. NEED 74-78 SEATS TO OPEN DOOR TO REVISE CONSTITUTION Abe said in January the LDP wanted to win a combined two-thirds majority with Komeito and like-minded opposition parties to open the path to revising the U.S.-drafted, postwar pacifist constitution for the first time. To do so, the ruling bloc, along with the pro-revision Initiatives from Osaka party and another tiny conservative party, need a total of 78 seats, up from 62. That threshold falls to 74 if one includes four independent upper-house lawmakers who are half-way through their six-year terms and support constitutional revision, according to Kyodo news agency. Formal amendment of the constitution requires approval by two-thirds of both houses of parliament and a majority of voters in a referendum. Abe's ruling bloc already has a two-thirds majority in the lower house. (Reporting by Kiyoshi Takenaka; Editing by Linda Sieg and Robert Birsel)