NEW YORK — Jon Lester set Major League Baseball records for largest signing bonus and biggest upfront payment with his $155 million, six-year deal with the Chicago Cubs.

The pitcher’s contract calls for a $30 million signing bonus, of which $15 million is due by April 1, a person familiar with the agreement told The Associated Press on Sunday. The person spoke on condition of anonymity because those details have not been announced.

The previous high for a signing bonus had been Vernon Wells’ $25.5 million under a $126 million, seven-year deal with Toronto that covered 2008-14 and was announced in December 2006. Wells’ bonus was payable in three equal installments on March 1 each year from 2008-10.

Lester’s upfront payment tops a mark set Dec. 8 by Cuban defector Yasmany Tomas. The Arizona Diamondbacks agreed to a $14 million signing bonus for the Cuban outfielder-third baseman, all payable within 30 days of the deal’s approval by Major League Baseball.

Tomas broke a record that had stood since January 1993, when Cecil Fielder agreed to a $36 million, five-year contract with Detroit that included an upfront signing bonus of $10,187,500.

Chicago and Lester spread out the rest of the signing bonus in three stages, with $2.5 million payments due by Dec. 31 in 2018 and 2019, and a final $10 million installment by Sept. 15, 2020.

Lester’s deal includes an option for 2021 that, if it becomes guaranteed, would make the deal worth $170 million over seven seasons.

Lester was 16-11 with a career-best 2.46 ERA and 220 strikeouts this year. He is 116-67 with a 3.58 ERA in nine big league seasons.