The National Labor Relations Board has issued a final ruling dismissing unfair labor charges filed by the union representing about 700 workers at Hawaiian Telcom Inc.

The NLRB’s office of appeals upheld a decision in May by the board’s regional director that concluded negotiators for IBEW Local 1357 and the company had reached an impasse after bargaining in good faith during contract talks last year.

Union members rejected two tentative contract proposals that were presented to them by union leaders during the bargaining. The impasse led to the company unilaterally imposing its “last best, final” contract offer on Jan. 1.

IBEW officials appealed the regional director’s ruling, but were denied in a letter sent to the union Aug. 17. “The appeal is denied substantially for the reasons in the regional director’s letter of May 29, 2012,” wrote Yvonne Dixon, director of the NLRB Office of Appeals.

“In particular, the following factors were taken into consideration: the movement of the parties during their negotiations, the employer’s business justification for its takeaways, the importance of the issues on which disagreement remained (especially pension), the rejection on two occasions of ratification by the members, the absence of any further proposals or calls for additional meetings after the employer rejected the union’s proposal that all issues other than the pension plan be removed, and the unchallenged language in the subsequent Dec. 21 update that the parties acknowledged that ratification did not appear achievable,” according to Dixon.

“For these reasons, and particularly for those more fully explained in the regional director’s letter, there is no basis for issuing complaint. Accordingly, further proceedings are unwarranted,” Dixon wrote.