As a part of its cost-reduction plans affecting “all of the company’s business segments, as well as various corporate functions,” Motorola Inc. announced in a regulatory filing on Tuesday that it would layoff 400 more workers, in addition to the earlier announced 1,500 job-cuts in the fourth quarter.

The latest job-cuts will enable the struggling mobile phone maker to add $25 million in pre-tax charges, resulting in overall pre-tax charges of almost $189 million in the fourth quarter.

In its filing with the US Securities and Exchange Commission, Motorola said that the fourth-quarter job cuts, chiefly from the mobile devices segment, were expected to result in charges totaling $104 million. The cost-reduction plan on the whole, comprising job-cuts up to a total of 3,000, is aimed at helping the company save nearly $800 million in 2009.

Motorola also said earlier in the month that it intends taking a few other moves like - cutting the salaries of its two top executives; suspending contributions to its 401(k) worker retirement plan; freezing its pension plan; and stopping some of the pay increases.

After the recent floundering of its former flagship business of selling wireless devices, Motorola focused on its home entertainment and emergency-response communications businesses, but these too had to be scrapped earlier this year, because there were hardly any buyers!