ESPN.COM reports that the decision dealt another blow to players who fear that a deal between the Orix BlueWave and Kintetsu Buffaloes could cost hundreds of jobs, and lead to more mergers reducing the sport from two leagues to one.
Presiding judge Kazuyoshi Harada upheld a district court ruling allowing the merger to proceed, rejecting an appeal by members of the Japanese baseball players' association, Tokyo High Court spokeswoman Chieko Kamiyama said.
The ruling came as the players' association convened at a hotel in western Kobe city to decide whether they should strike if the teams' owners approve the merger later this week.
It would be the first strike in Japanese baseball, and would come 10 years after the US major league players went on strike in 1994.
The baseball owners are expected to approve the merger at their meeting Wednesday.
Japanese professional baseball's Pacific and Central Leagues currently have six teams each. But many owners in the less profitable Pacific League are said to favour a single league of 10 teams to cash in on the higher revenues of the Central League's Yomiuri Giants.
