(Reuters) - AutoNation Inc AN.N, the largest U.S. auto dealership chain, said on Monday Chief Executive Officer Cheryl Miller has been granted a leave of absence for health reasons.

The company, whose shares continued to fall for a second straight day, dropping as much as 4.5% to $32.10, declined to provide more details about the CEO’s health.

Coronavirus-led lockdowns have severely hurt sales of automobiles globally as buyers postpone purchases, forcing automakers to shut production at several factories.

Earlier this month, AutoNation said its sales of new and used vehicles halved in the last two weeks of March due to the COVID-19 pandemic, forcing the company to place about 7,000 employees on unpaid leave.

Miller, 47, served as the company's chief financial officer before being appointed as CEO in July last year. Since joining AutoNation in 2009, Miller has led several strategic initiatives, including the building of the company's partnership with Alphabet Inc's GOOGL.O Waymo and helping the dealership chain achieve investment-grade status.

The company said it has appointed Mike Jackson, executive chairman of board, to serve as the CEO until Miller returns. (bit.ly/2xgdpPl)

To combat the coronavirus crisis, AutoNation has taken measures to cut costs, including temporary pay cuts for staff, curtailment of advertising expenses and postponing over $50 million in capital expenditure through the second quarter of 2020.

AutoNation shares have fallen more than 30% this year.