Most labor unions in the Japanese auto industry demanded Wednesday a base pay increase of ¥4,000 a month for this year's "shunto" spring wage talks despite the deteriorating business environment.

The demand was based on the uptrend of prices of goods that started early last year, but the negotiations will be tough at a time when many carmakers announced forecasts in recent weeks for red ink for the business year ending March 31.

The ¥4,000 raise demand also comes as automakers have slashed thousands of domestic temporary workers and some full-time workers mainly abroad to reduce labor costs.

Unions at nine out of 10 car and truck makers demanded a ¥4,000 pay increase, while the remaining union at Mitsubishi Motors Corp. did not demand any hike.

Some carmakers that do not introduce a constant pay rise also demanded additional money to maintain the existing salary levels or to pay for a raise for good performance. For instance, unions of Toyota Motor Corp. demanded ¥7,100 per person on average and the Nissan Motor Co. union demanded ¥7,000 per person on average.

"We think highly of the unions' demand that are decided by themselves based on our policy," said Koichiro Nishihara, president of the Confederation of Japan Automobile Workers' Unions (JAW).

The 10 car and truck makers, as well as a motorcycle maker and a brake maker, belong to JAW. The manufacturers are expected to give their answer in a month.

The carmakers said that the demand does not reflect the harsh business environments.

"Under the current situation, our focus is how to survive, (not) a base pay increase," Nissan Senior Vice President Hitoshi Kawaguchi told reporters.