TOKYO — As the mini-vehicle market continues to heat up here, rivalries between Japanese automakers are not being taken lightly.

The fiercest competition falls to industry leader Suzuki Motor Corp. and runner-up Daihatsu Motor Co. Ltd. Tension sped up in February after Daihatsu took the sales lead by 100 vehicles. Suzuki roared back, ending the month with 16,000 minicar sales compared with Daihatsu's 12,000 sales.

Total estimated new-car sales in February for the two, including trucks and non-minicars, reportedly reached about 50,000 for Suzuki, giving it a 31% market share. Daihatsu took a 28% share with 45,000 sales. Still, the margin between the two is shrinking, from 3.4% same period a year ago to 3% today.

Analysts credit Daihatsu's success to its cab-over Atrai van, which outsold Suzuki's Every two months in a row. The Daihatsu Move passenger car also has gained on Suzuki's popular Wagon R, shaving the margin between them to 1,000 units.

Daihatsu is targeting the 1999 sales year at 470,000 units, up 19.4% from 1998, a recent report says. The automaker hopes to expand market share by 3% to 28.8%. A top Suzuki executive says his company has set its sights on a record-high 560,000 vehicle sales goal for 1999.

Industry observers say Daihatsu is feeling pressure from Toyota Motor Corp., which last October raised its stake in the mini-maker from 32% to 51%, to take 40% of the mini-market share. While Daihatsu does not plan to compete with Toyota's subcompact models, the company does plan to take advantage of the parent company's sales clout. The race comes down to the wire this month, which marks both the end of the fiscal year and the peak period for minicar sales.