(Reuters) – Frontier Communications urged shareholders on Friday to vote for a $20 billion takeover bid from Verizon, saying that it had reviewed interest from other potential buyers and found the telecom giant’s proposal as the most favorable option.

The fiber-optic internet provider said Verizon’s final offer presents “a superior value over all other potential paths, including Frontier’s ambitious standalone plan.”

Frontier did not disclose the names of the other bidders.

Verizon agreed in September to acquire Frontier as the U.S. telecom giant looks to build its fiber subscriber base and better compete with rivals such as AT&T.

However, some Frontier investors are concerned about the deal stating Verizon’s $38.50 per share offer is too low, according to a Reuters report.

Verizon CEO Hans Vestberg said on Tuesday the company gave its “best and final” deal and was confident it was “good for all stakeholders”.

The offer is “highly attractive and creates significant value for stockholders … and a significant premium to all other measures of Frontier’s historical stock performance,” Frontier said on Friday.

“There are no assurances that Verizon or any other bidder will return with another offer,” it added.

If the merger falls through from Frontier’s end it may be required to pay Verizon a termination fee of $320 million and if Verizon terminates the deal, it may have to pay Frontier $590 million, Verizon said in a filing on Friday.

(Reporting by Harshita Mary Varghese in Bengaluru; Editing by Shounak Dasgupta)