Charles Okah and Obi Nwabueze were convicted for facilitating and financing the blasts during national celebrations in the capital Abuja.
The pair were also sentenced over a second attack earlier the same year in Warri, Delta State that killed two people.
Okah is the brother of oil militant Henry Okah, the suspected mastermind of the two plots who is already serving a 24-year prison sentence in South Africa.
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Henry Okah was at the time the presumed leader of the Nigerian militant group Movement for the Emancipation of the Niger Delta (MEND) which was in conflict with the government over the sharing of oil revenues.
Nigeria was left in shock when 2010 celebrations marking the 50th anniversary of the country's independence from Britain, which was attended by then President Goodluck Jonathan and foreign leaders, ended in tragedy when two cars laden with bombs exploded.
"The convicts are hereby sentenced to life imprisonment," Federal High Court Justice Gabriel Kolawole said of Charles Okah and Nwabueze on Wednesday in Abuja.
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He said the two defendants had tried to "frustrate the trial" and delay the outcome of the proceedings which began in December 2010.
The pair claimed to be innocent and said they were arrested for political reasons.
Two other suspects were also arrested over the bombings, but one died in custody and another was sentenced to life in prison in a separate 2013 trial.
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