The Massachusetts House and Senate have approved a compromise version of a bill that would allow for a $1 billion expansion of the Boston Convention and Exhibition Center.

Supporters of the bill say it is necessary to keep the facility competitive with similar convention centers in other cities, and the expansion will create jobs, provide additional tax dollars and boost tourism.

The bill authorizes a 1.3 million square foot expansion.

Supporters said the convention center in South Boston, which opened in 1997, isn’t large enough and doesn’t have enough adjoining hotel rooms to attract many large-scale national and international meetings, which are now going to other cities.

The bill still needs a final vote in both chambers before being sent to Gov. Deval Patrick for his signature.