The Vancouver-based company said Friday that a bureau within the U.S. Federal Trade Commission completed its review and granted an early termination of the waiting period under the Hart-Scott-Rodino antitrust act.
The approval was the last regulatory hurdle for the deal.
MDA is best-known as the maker of the robotic arms used on the International Space Station and the now-retired U.S. space shuttles.
The company has approximately 16 employees in Ottawa.
Concerns had been raised about the review after the U.S. Department of Justice requested more information regarding the deal and MDA.
The company's shares climbed more than 25 after the deal was first announced, but fell back after the U.S. government made its second request for information related to MDA's Montreal satellite communications antenna and payload business.
CIBC analyst Stephanie Price raised the bank's rating on the stock following the regulatory approval to "sector outperformer" and increased the price target on the stock to $66 from $54.50.
"The acquisition allows MDA to gain critical mass in the commercial satellite manufacturing industry and better positions the company to win U.S. defence and intelligence work," Price wrote in a note to clients.
Scotiabank analyst Andy Ko also raised his price target on MDA to $62 from $60 on Monday.
Ko called the SS/L deal a major step by MDA to expand and increase its commercial market business.
"MDA is positioned to benefit from greater diversification of its revenue base towards commercial customers and increased exposure to a large market for commercial satellite manufacturing and to leverage its expanded U.S. presence," Ko wrote in a note to clients.
The anti-trust approval followed a review by the Committee on Foreign Investment in the United States, which found "no unresolved national security concerns with respect to the transaction" last month.
MDA agreed in July to buy SS/L from Loral Space & Communications for US$774 million cash for SS/L's equity and US$101 million for certain real-estate used by the California-based company. Loral Space - which is also a partial owner of Ottawa-based Telesat - will receive US$112 million in cash dividends from SS/L.
SS/L is a supplier of commercial communications satellites.