The deal was announced as U.S. Defense Secretary Robert Gates kicked off a tour of the region to discuss growing international concern over Iran's nuclear program.
The Bell Helicopter deal includes commercially designated Huey II aircraft, pilot and maintenance training, spares, special tooling and dedicated service representatives.
"This contract award is the result of a true team effort," said John L. Garrison, Bell Helicopter president and chief executive officer. "We are delighted to partner with AMCOM, DCAA and DCMA to provide the Yemen government with aircraft and support that not only adds value to their mission, but are expected to be delivered ahead of schedule," he said in a company statement.
The aircraft are to be delivered in January and are expected to be operational within a year. A spares package has also been included in the $27 million deal.
"Built on the foundation of proven reliability, the Huey II delivers increased mission capabilities and the performance enhancements needed to ensure the success of the Yemen government's mission requirements," said Larry Roberts, senior vice president commercial business.
The tender was launched in January and Bell says all four aircraft are complete.
Bell Helicopter is a subsidiary of Textron Inc. and is an industry-leading producer of commercial and military, manned and unmanned vertical lift aircraft and the pioneer of the revolutionary tilt rotor aircraft.
"Based on the proven Bell UH-1H helicopter, the Huey II configuration adds a more powerful engine, new dynamic components and tailboom, a new navigation and communication suite, and complete rewiring to an existing hull; significantly increasing in hover performance and gross weight, while lowering direct operating costs," the company said of its winning helicopter.
Under the deal, at least 12 Yemeni pilots and 32 maintenance technicians will be trained by Bell Helicopter experts.
While in Oman, Gates discussed Iran's disputed nuclear program with Sultan Qaboos bin Said as well as the growing threat in Oman's neighbor, Yemen.
The visit comes amid the disclosure of hundreds of thousands of secret U.S. diplomatic memos on the WikiLeaks Web site. Documents released include cables that depicting Arab leaders deeply threatened by Iran's nuclear ambitions and urging Washington to take military action. Since the link, U.S. officials have been trying to allay concerns by allies and partners unnerved by the leaked files, which included embarrassing revelations and harsh assessments of an array of leaders.