The Baker administration is reviving the idea of expanding the Boston Convention and Exhibition Center in Boston's Seaport and wants permission to sell the Hynes Convention Center in the Back Bay as part of a consolidation of the city's event and convention space.

Gov. Charlie Baker's budget office announced Monday afternoon that the administration will file legislation to authorize the Massachusetts Convention Center Authority to sell the Hynes and set the proceeds from the sale aside to help fund an addition to the BCEC that would open 200,000-square-feet of additional space, a significantly smaller expansion than the one approved by state lawmakers just before Baker took office.

Selling the Hynes and expanding the BCEC will enhance economic activity in both neighborhoods — Back Bay and the Seaport — and will create the possibility for the redevelopment of the desirable Hynes location, Baker said.

"Boston is a popular convention destination, and there has been market demand for larger, more flexible event space in recent years. This expansion will meet demand, unlock greater economic potential, and support the creation of new jobs," Baker said in a statement. "Our plan will make Boston's convention space more efficient and maximize new economic opportunities in both the Seaport and the Back Bay, benefiting the City of Boston and the Commonwealth."

Around 500,000 square feet would be added to the Boston Convention and Exhibition Center under Gov. Charlie Baker's plan. (State House News Service)

The new proposal comes four years after Baker indefinitely suspended a $1 billion BCEC expansion that had been approved by the Legislature prior to his election and expressed deep misgivings about the BCEC's ability to pay off the anticipated debt without impacting the state budget.

Boston Mayor Martin Walsh is on board with the proposal, which also includes the transfer of a 12-acre parcel of land behind the BCEC to the city of Boston. Baker's administration said the parcel is not necessary for its BCEC expansion plan.

"As Boston continues to serve as a regional hub for economic activity and growth, the state's proposal presents a new opportunity to expand the Convention Center and bring a significant piece of land back to Boston, benefiting the South Boston Waterfront and city overall," Walsh said in a statement released by Baker's office. "I look forward to discussing this proposal with the Legislature and staying engaged through this process as it moves forward."

The 200,000 square feet of new space at the BCEC would be used for a 100,000-square-foot exhibition hall, a 60,500-square-foot ballroom and additional meeting rooms, the administration said. With the expanded capacity and a greater variety of room types available, the BCEC "will be positioned to capture greater market share for large multi-day conventions and shows and accommodate bookings that might otherwise have gone to the Hynes," the administration said.

The administration's plan will be presented in full at Thursday's meeting of the MCCA's board of directors.

In 2014, the Legislature and Gov. Deval Patrick authorized $1 billion in state bonding to expand the BCEC by about 1.3 million square feet.

The expansion plan the governor is putting forth now appears to be far smaller in scope than what Patrick and the Legislature sought to do five years ago. The administration did not respond to inquiries about whether the 2014 authorization remains valid and whether the newest Baker plan relies on it in any way, but the administration's press release said the proposal "will require no new state borrowing."

Rep. Jay Livingstone, a Boston Democrat, lives about two blocks from the Hynes, and though it's slightly outside of his district, he's familiar with the neighborhood.

"I'm not sure. I don't really have the details. It came as a surprise and I'm looking forward to getting more details from the governor about this plan and what it could generate and where the money will go," Livingstone said.

Baker described the site of the Hynes Convention Center as a "valuable parcel for redevelopment in the heart of the city," but Livingston noted that Weiner Ventures recently walked away from plans to develop two-towers at 1000 Boylston St.

"What the development opportunity is right now, I'm not sure. But I'm seeing mixed signals," said Livingstone, who voted for the expansion of the BCEC in 2014 when the sale of the Hynes wasn't part of the financing plan.

The BCEC opened in 2004 and has seen Boston's Seaport district get rapidly and dramatically built out around it. The Hynes opened in 1963 and was rebuilt in 1988. The Baker administration said the Back Bay facility would need about $200 million in capital investments over the next decade just to maintain its current state.

The administration said the property "could be put to more productive use through creative redevelopment."

State House News Service reporter Matt Murphy contributed to this report.