Apple Inc Chief Executive Tim Cook received a one-time stock award worth nearly $400 million, the largest given by a company in a decade.

The company's board granted Cook 1 million restricted stock units (RSUs) to signal its confidence in Cook after Steve Jobs turned over the helm of the iPhone and iPad maker to his long-time lieutenant in August.

The stock award, half of which vests in 2016 and the remaining half in 2021, was worth more than $376 million, based on the closing price of Apple's shares on August 24, 2011, the company said in a Monday proxy filing.

As far as a singular award, we haven't seen anything this large in a long time, said Aaron Boyd, head of research at Equilar, an executive compensation data firm.

The only one-time stock award in recent memory that was worth more, said Boyd, was the January 2000 stock option package that Apple gave co-founder Steve Jobs. The 40 million options in that award were valued at more than $600 million at the time, Boyd said.

Jobs, who was ousted from Apple in the mid-1980s, returned to the company in 1997 and went on to transform Apple into the world's most valuable technology company with a string of hit products including the iPod, the iPhone and the iPad.

Jobs, who died in October after a years-long battle with cancer, owned 5.5 million shares of Apple, according to the filing.

Jobs received $1 a year in salary during the past three years, according to the filing, while Cook received a salary of about $900,000 in 2011.

Apple said Cook's award was a retention and promotion tool, as well as recognition for running the company during Jobs' previous medical leaves of absence.

The Board views his retention as CEO as critical to the Company's success and smooth leadership transition. The RSU award is intended as a long-term retention incentive, Apple said in its statement.

Shares of Apple closed Monday's regular trading session down 67 cents at $421.73, after reaching an all-time high of $427.75 earlier in the day.

(Reporting By Alexei Oreskovic and Edwin Chan; Editing by Richard Chang and Steve Orlofsky)

Steve jobs Apple inc. Apple Tim cook