Plug Power(PLUG) - Get Report shares fell 6% on Wednesday after Roth Capital downgraded the shares to sell, saying that the fuel cell firm's widely covered partnership with Amazon will dilute shareholders' value.

Roth also trimmed its Plug price target to $1.30 a share from $2.25.

Plug shares traded at $1.93 in early activity, down 11 cents or 5.6%.

"Plug reported weak first-quarter 2017 earnings," the analyst said. "Material points in the 10-Q, shareholder letter, and company call are that anchor customer Wal-Mart(WMT) - Get Report will dramatically reduce purchases in 2017, and the $70m Amazon(AMZN) - Get Report  revenue expected in 2017 is not additive to guidance," the report concluded.

The company saw its shares jump handsomely on a partnership agreement with Amazon in April when online retailer acquired the right to buy up to 23% of Plug and use its technology to speed up work in its warehouses.

Latham, New York-based Plug said in a Wednesday press release that it's named the CFO at Boston-based Entegris,  Gregory Graves to its board following two directors' decision to leave the firm.

More of TheStreet's top stories:

plug power, plug, fuel cell, jeff bezos, amazon