The arrival of the Gabon worldwide forward and the capture of Henrikh Mkhitaryan as part of the Sanchez deal from United is said to have convinced Ozil to sign a new deal.
The Germany international's current deal is due to expire at the end of June but he is expected to commit himself to a new long-term contract at Emirates Stadium.
Amid growing speculation of a new contract at Arsenal, Ozil tweeted: 'Had a busy day signing things'.
However, the Gunners have successfully negotiated a new contract with the Germany worldwide, who will now earn £350,000 a week before tax; more than any other player at the club.
The German global has penned a new three-and-a-half deal which will keep him at the club until 2021, removing any doubt that he could leave for the likes of Barcelona in the summer.
The north London club have been in talks with Ozil since last season and look to have finally made a breakthrough. Deal agreed last weekend, signed at Colney this morning.
But any offer is likely to be rejected as Arsene Wenger doesn't want Ozil going anywhere.
He joined the Gunners from Real Madrid in 2013 for a then club record £42.4m.
The 29-year-old playmaker had been linked with several clubs, including Manchester United, who signed Sanchez in a swap deal for Henrikh Mkhitaryan in January.
According to reports, Ozil's new pay will see the player earn £350,000 a week before tax.