People Express holders will vote on a merger offer.

Approval of the offer by Texas Air Corp., involving an exchange of securities valued at $115 million, would be the final hurdle in the Houston-based firm’s attempt to take control of the ailing discount carrier and would make Texas Air the nation’s largest airline company. A spokesman said that most shareholders have mailed in ballots, and that the rest will vote at a meeting today at a company office in Newark, N.J. More than 88% of the holders of the company’s public debt securities already have approved the deal. People Express lost $245.4 million in the first nine months of 1986.