(Updates with responses from the company and the union.)

Starbucks' (SBUX) unionized employees negotiating a first-time collective bargaining agreement rejected the latest company offer, Bloomberg reported Friday, citing a statement by the SBWorkers United.

The company proposal was turned down by 81% of the delegates voting this week while 14% voted to accept and the rest abstaining. The talks have continued for roughly three years, with the sides previously resolving some of the contract terms, such as workplace safety and employee dress codes, but still do not agree on pay increases and health care benefits.

A Starbucks spokesperson referred MT Newswires to a company from earlier. By turning down the company's latest offer, the union negotiators undermined all the prior progress, nearly 200 hours of talks and more than 130 proposals exchanged, according to the statement.

"The union's actions, unfortunately, only cause further delay in reaching a mutual agreement on the path forward." the spokesperson said.

Michelle Eisen, a Starbucks barista and a union delegate, said they are asking the company "to invest in our wages and benefits, which can be done in a number of ways, and that fundamentally means putting more money into the contract."

The union represents more than 550 individual Starbucks locations around the US.