Mike Trout is set to own the largest contract in professional sports history.

The Los Angeles Angels and the 27-year-old outfielder are finalizing a record-breaking, 12-year contract worth more than $430 million, sources told ESPN's Jeff Passan.

Trout's new agreement includes a full no-trade clause and no opt-out provisions, sources told Bob Nightengale of USA TODAY Sports, who reported that because the superstar is still under contract for two more seasons at $33.25 million per year, the arrangement is technically a $363.5-million extension that begins in 2021.

The Angels have been negotiating a new deal with Trout for months, but the parameters were not agreed upon until about 2 a.m. ET on Tuesday, Nightengale added.

Trout's expected average annual salary in the new deal will best the previous record held by Arizona Diamondbacks pitcher Zack Greinke ($34.4 million) and his overall contract will top the $330-million deal that Bryce Harper signed with the Philadelphia Phillies on Feb. 28 as the most lucrative in MLB.

Trout, a two-time American League MVP and a seven-time All-Star, owns a career slash line of .307/.416/.573 with 240 home runs and 648 RBIs through 1,065 games.

Since debuting in 2011, he's accumulated 64.9 WAR, according to FanGraphs, which is tops among all active players and ranks 89th all time.

However, the Angels haven't taken advantage of Trout's elite production. They've only reached the playoffs once since he joined the team, losing all three games of the 2014 American League Division Series to the Kansas City Royals.