TOKYO (AP) _ A Socialist-led delay tactic in Parliament today bogged down efforts by conservatives to pass a bill paving the way for the dispatch of Japanese troops overseas for the first time since World War II.

The governing Liberal Democratic Party had hoped to speed the divisive bill through the Upper House. But the Socialists led a so-called ''cow walk'' - a snail-paced march to the podium to present votes.

Since the Socialists have succeeded in putting several other procedural measures up for vote first, it was unclear when the final vote on the troops bill might come. A slow walk on the first measure lasted all night and into this afternoon.

''It is a question now of how long we can physically endure,'' said Makoto Tanabe, who heads the Socialists. ''We will fight this to the end.''

The bill is expected to pass eventually because the Liberal Democrats hold a narrow majority coalition in the upper chamber with two moderate opposition parties and have a solid majority in the more-powerful lower house.

Military issues have been a sensitive area for the Japanese throughout the post-war era. Public opinion tends toward pacifism, though a significant right-wing movement strongly advocates a beefed up military role.

The troops legislation was proposed by the conservative Liberal Democrats during the Gulf War in response to criticism that Japan was willing to contribute money but not people to international peacekeeping efforts.

It would create a 2,000-member corps for U.N. peacekeeping operations, but makes Japanese participation in the more hazardous areas of peacekeeping - such as separating warring armies - contingent on passage of another bill.

The Socialists - Japan's largest opposition party - Communists and many academics oppose the bill because they say it violates a constitutional ban on using force to settle international disputes.

The bill has also met with anxious reactions from some of Japan's Asian neighbors, who fear a revival of Japanese militarism.