Dan Biggar chose to stay in Wales because he "did not want to risk" his place in the national team.
The 26-year-old fly-half won BBC Cymru Wales Sport Personality 2015 after an outstanding international season.
Coach Warren Gatland has a limit on the number of non-Wales based players he can select, and Biggar says that was a factor when he agreed a dual contract.
"Playing in front of 70,000 whenever you pull on that [Wales] shirt is pretty special," said Biggar.
"I didn't want to risk that by moving away.
"It took a long time [to decide to stay] because your career is short and there were some great offers on the table."
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Biggar's deal will see him remain with Ospreys potentially until the 2019 World Cup with his salary paid 60% by the Welsh Rugby Union and 40% by the region.
The dual contracts are designed to keep high-profile players in Wales.
His Ospreys and Wales half-back partner Rhys Webb is also in talks over extending his deal while second-row Alun Wyn Jones' contract ends next summer.
One of the terms of the funding and management agreement between the WRU and the regions means Gatland can pick only two players who have chosen to play outside the country rather than accept a contract with one of the regions.
Biggar says loyalty to the Ospreys also played a part in his decision.
"Ospreys is somewhere I've racked up a fair amount of games and I've got some loyalty towards there as well," he added.
"It was a long a long, hard decision.
"But I'm here for the next two years, guaranteed, and then we'll see where we go from there."