Gree today announced that the it is expanding its U.S. games business while simultaneously shrinking its U.S. offices.

In a press release, the Japanese mobile games publisher and platform holder announced a $3 million investment in developer MunkyFun and that a reorganization in its U.S. offices would lead to layoffs.

Gree, which recently announced the closure of mobile social gaming platform, OpenFeint, is focusing its U.S. business primarily on its own titles and developer partner titles. As part of the company’s internal U.S. reorganization, a majority of the Gree games platform team will be transitioned to new departments with redundancies in some areas. The overall Gree Platform business will begin transitioning to its operations in Tokyo as a part of this change

The closure of OpenFeint, which is an in-game social-networking service, means that Gree no longer needs anyone in the U.S. to manage that platform. So the publisher will shuffle some of those people into other jobs while cutting others loose.

We’ve contacted Gree to determine the number of employees that were laid off, but the company was unwilling to provide further comment.

Gree the company runs the Gree Platform service, which it provides to outside developers (as well as its internal studios) to create a unified friends list, leaderboards, and other social tools for the end-user. Gree purchased OpenFeint to acquire its users and player behavior data, although it’s handling of that product has rubbed some developers the wrong way.

In terms of its U.S. investments, MunkyFun is the first game to benefit from Gree’s new mobile investment fund. The studio previously released titles like My Horse and Bounty Bots. Gree’s already released Monster Quest and MLB: Full Deck in the states as it attempts to recreate here the success it’s had in Japan.