The MBTA has pulled the plug on a plan to improve Wi-Fi on commuter trains by installing hundreds of 75-foot-tall telecommunication towers along the tracks.

The transit agency Thursday rejected the proposal by its private contractor, BAI Communications, which was expected to begin installing the towers soon. The T said BAI Communications’ proposal for 320 new tall towers was well beyond what the agency anticipated, and it directed the company to submit a new plan.

The BAI proposal had triggered strong backlash from suburban residents and municipal leaders, who complained the towers were too tall, too intrusive, and that the MBTA had not provided enough notice of the project. At a MBTA board meeting in late July, dozens of members of the public spoke unanimously against the plan, citing concerns about property values and public ­input.

Alex Vispoli, an Andover selectman who led the opposition in his town, said he was “pleasantly surprised’’ the MBTA stepped in to reject the towers.

“I think it’s a direct result of the grass-roots discussion that’s . . . developed into a real groundswell’’ of opposition, said Vispoli, who wants the T to come back with a more acceptable plan to improve Wi-Fi on the rails.

Steve Poftak, interim general manager of the Massachusetts Bay Transportation Authority, said in his letter to BAI that the towers were too high, and that the T had originally “contemplated a more modest proposal.’’ The agency expected the Wi-Fi system to be installed on “short’’ monopoles or existing utility poles near rail lines.

Moreover, he questioned BAI’s intention to use the larger poles in order to sell excess capacity on the Wi-Fi network to other telecommunication companies. While the T said it had allowed BAI to lease “excess space’’ on the tower network to third-party companies, it contended that BAI was overbuilding in order to maximize that space.

Poftak said BAI could submit a new plan that takes “into account the community concerns with pole size and location that have been raised.’’

The MBTA declined additional comment.

BAI spokesman Raymond Howell said the firm “looks forward to working with the ­MBTA and local officials on a system that delivers these benefits while minimizing impacts to areas located along the Commuter Rail’s existing corridors.’’

At the July board meeting, Poftak said while the T could not end the contract without justification, it did have the power to approve details of BAI’s installation. And in his letter Thursday, Poftak also cited other work along the rail system as justification for delaying the Wi-Fi work — notably the Green Line extension and federally mandated safety systems.

BAI was slated to spend $140 million on the installation of the poles, and — after earning back the costs of installing the towers — share 7.5 percent of the revenue related to the project with the T. The revenue could include advertising and leasing space on the towers.

Poftak had previously said the T would receive a relatively small amount of money from the contract: $20 million to $40 million over 20-plus years.

One of those 75-foot towers was supposed to go right ­behind the home of John McTighe. The Ipswich resident testified at the T’s July meeting that he only learned about the tower when he saw a map of the proposed locations on the website of a local news station.

“Nobody notified me. Nobody came out to my door,’’ he said. “I’ve been in the house for over 25 years — I’m not a hard person to find.’’

The contract was originally signed with Boston-based inMotion Wireless in 2014, under the administration of former governor Deval Patrick. InMotion was acquired earlier this year by BAI, which is based in Australia. The Baker administration amended the contract earlier this year to clarify the project timeline.

The company was on the verge of installing the towers, with service on portions of the network scheduled to go live before the end of the year. The entire Wi-Fi network was ­expected to be completed by August 2018.

But with mounting public outcry that included a letter from the state’s congressional delegation, the T put the project on hold in late June for a review.

Even members of the ­MBTA’s governing board expressed concerns about the project at their July meeting, with one, Lisa Calise, criticizing BAI for not communicating with the public. She said the company’s response to public complaints was “unacceptable.’’

Adam Vaccaro can be reached at adam.vaccaro@globe.com. Follow him on Twitter at @adamtvaccaro.