Motient Corp. last week said the signature of a binding term sheet with Telecom Satellite Ventures Inc. to acquire that company’s interest in Mobile Satellite Ventures LP and its general partner MSV GP Inc.

According to Motient, the company will issue 8.2 million shares of its own common stock in exchange for the 2.3 million Mobile Satellite Ventures limited partnership units held by Telecom Satellite Ventures. The net effect of this transaction will increase Motient’s ownership stake in Mobile Satellite Ventures by about 5.9 percent to about 44.5 percent.

According to Motient, Raj Singh, the principal of Telecom Satellite Ventures, has agreed to serve as an advisor to Motient should Motient ask him to do so after the closing. Additionally, a Jan. 11 Form 8-K filed with the Securities and Exchange Commission stated that Motient will acquire the rights held by Telecom Satellite Ventures to receive shares of TerreStar Networks Inc., currently a wholly owned subsidiary of Mobile Satellite Ventures. If TerreStar were to be spun off by Mobile Satellite Ventures, Motient would obtain direct ownership of TerresStar in approximately direct proportion to its ownership of Mobile Satellite Ventures.

“We are delighted not only to increase our stake in a company whose prospects we deeply believe in, but to welcome Dr. Singh as a major shareholder of Motient,” Steven Singer, Motient chairman, said in a press release. “It is our hope and belief that this transaction will open up an entirely new range of opportunities and strategic options for Motient.” A spokesman for Motient declined to discuss the details of the acquisition and its future impact on Motient and Mobile Satellite Ventures.

The Form 8-K noted that the transaction is scheduled to close in February, subject to specified conditions.