BioTek Instruments Inc., a closely held U.S. medical device maker, is exploring options including a sale amid interest from rivals and investment firms, according to people familiar with the matter.

BioTek could be valued at about $1 billion in a sale, said the people, asking not to be identified because the matter is private. Health care companies and investment funds have expressed preliminary interest in acquiring the whole company or a stake, the people said.

The Winooski, Vermont-based company’s deliberations are continuing and a final decision on whether to pursue a deal hasn’t been made, the people said.

"BioTek is a privately held, family owned company," Julie Bond, senior marketing operations manager with BioTek, said. "We frequently do receive inquiries from potential buyers but it’s our policy not to comment on any market rumors."

Founded in 1968, BioTek makes cell-imaging systems, test-tube plate readers, incubators and other instruments and software for life sciences research and drug discovery, according to its website. Last year, it announced that it would collaborate with Agilent Technologies Inc. to provide a new kind of cellular analysis system.

About $30.7 billion in deals involving health-care products companies have been announced so far this year, an increase of almost 30 percent from the same period in 2018, according to data compiled by Bloomberg. That includes General Electric Co.’s agreement to sell its biopharma business to Danaher Corp. for $21.4 billion and Johnson & Johnson’s $3.4 billion acquisition of surgical robotics company Auris Health Inc.