Athenahealth on Monday announced it had received an unsolicited cash offer from Elliott Management, the hedge fund of activist investor Paul Singer, to buy the health information technology company for roughly $6.9 billion.

Elliott Management offered $160 per share in cash, which represented a 27-percent premium on market price of athenahealth stock at the time.

Athenahealth opened offices in Belfast in 2008 and is now among the three largest employers in Waldo County with between 800 and 1,000 workers.

The company restructured earlier this year in response to pressure from Singer and Elliott Management, which owns an 8.9 percent share of the athenahealth. The restructuring included layoffs of 500 workers, of whom roughly 20 were employed in Belfast.

Monday's offer from Elliott Management spoke positively about athenahealth as a business but said that "from a shareholder standpoint, owning athenahealth has been a disappointing experience."

"Given athenahealth’s potential, this reality is deeply frustrating," the letter read, "but the fact remains that athenahealth as a public company has not made the changes necessary to enable it to grow as it should and to create the kind of value its shareholders deserve."

Athenahealth released a statement Monday saying the company's board of directors "will carefully review the proposal to determine the course of action that it believes is in the best interest of the company and athenahealth shareholders."