WASHINGTON - Starbucks Corp Chief Executive Howard Schultz declined an invitation from 11 senators to testify on March 9 on the coffee company's compliance with federal labor law, according to a letter seen by Reuters late on Tuesday.

Last week, U.S. Senator Bernie Sanders, who chairs a committee on labor issues, and 10 other members of the committee asked Schultz to answer by Feb. 14 whether he would take part.

Schultz, who re-joined Starbucks as interim CEO in April 2022, will "fully transition" out of the role next month, said Starbucks acting executive vice president and general counsel Zabrina Jenkins in the letter.

"Given the timing of the transition, his relinquishment of any operating role in the company going forward and what we understand to be the subject of the hearing, we believe another senior leader with ongoing responsibilities is best suited to address these matters," Jenkins wrote.

Sanders, who last month took over as chair of the Health, Education Labor and Pensions (HELP) Committee, said last week Starbucks "has fought their workers every step of the way, including refusing to bargain a first contract in good faith, delay tactics, and a significant escalation in union busting."

Sanders' office did not immediately comment on Starbucks' letter.

Starbucks said executive vice president and chief public affairs officer AJ Jones II is available and is the best person to address workforce policy matters. Jones is a former senior aide to Democratic Representative James Clyburn.

Starbucks Workers United has won elections at more than 260 U.S. stores and has lost about 70 elections since late 2021. The union is seeking increased pay and benefits, improved health and safety conditions and protections against unfair firings and discipline.

Starbucks says it respects the right of its employees to organize and to engage in lawful union activities. The company says it has held more than 80 single-store contract bargaining sessions since October.

(Reporting by David Shepardson; Editing by Shri Navaratnam and Jacqueline Wong)