WASHINGTON — As business leaders from the St. Louis region see it, growth and innovation are stifled by a shortage of immigrants that puts the area at a disadvantage competing with other cities.

In an initiative that might have been unthinkable not long ago, the St. Louis business community appealed to Congress this week for reforms that could bring in more foreigners at all skill levels and prevent immigrants here temporarily from being forced to leave.

Joe Reagan, president and CEO of the St. Louis Regional Chamber, on Thursday blamed stagnant population growth in St. Louis on obstacles preventing the arrival of immigrants.

“We know that to get to 4, 5 or 6 percent growth, that we’ve got to throw the doors open to St. Louis and be the most welcoming community we can for people from all over the world,” he said.

Reagan delivered his remarks at a conference sponsored by the Chicago Council of Global Affairs aimed at mobilizing Midwesterners as potentially far-reaching changes in the nation’s immigration policies take shape in Washington.

A report released at the gathering concluded that the Midwest urgently needs high-skilled, educated new people as well as low-skilled immigrants to sustain businesses.

“We aren’t the only land of opportunity. There are increasing options for talented people around the world,” said Joe Loughrey, former president of Indiana-based Cummins Inc. and a member of a task force behind the report.

A nine-member St. Louis-area delegation delivered much the same message in meetings with members of Congress from Missouri and Illinois.

The delegation represented the Regional Chamber as well as the St. Louis Economic Council, the St. Louis Development Corp. and other local entities and universities. The group included Bi-State Development Agency president and chief executive John Nations.

Despite general dysfunction in Congress allowing indiscriminate new budget cuts, prevailing wisdom holds that the political parties will reach agreement this year on immigration legislation for both practical and political reasons.

Reagan was among the local leaders who left for home after a two-day visit heartened by what they heard while making the rounds on Capitol Hill.

“What I found most surprising is how much hope there is,” Reagan said in an interview, noting a confluence of forces including Republicans’ need to react to a fast-changing electorate.

“They want more voices and they particularly want more out of the business community.”

At the conference, Reagan described a study last June finding that the St. Louis area’s 4.5 percent immigrant population ranks far behind immigrant populations in top American cities.

“If you look at our population growth, it looks like a bad EKG,” he said, speaking at the National Press Club.

Reagan held aloft the benchmark study, authored by St. Louis University economist Jack Strauss, that helped trigger the pro-immigration initiative.

Strauss, who accompanied the business leaders to Washington, concluded that a new flow of immigrants would spur job growth, boost overall income rates and increase housing prices in St. Louis.

Denny Coleman, president and CEO of the St. Louis Economic Council, described the findings as “a direct link between a lack of immigration and slower economic growth compared to other metropolitan regions.”

Coleman, part of the delegation in Washington, referred to immigration curbs now in place as “a totally self-defeating national policy.”

The delegation had meetings with Sens. Claire McCaskill, D-Mo., and Roy Blunt, R-Mo., Reps. Ann Wagner, R-Ballwin, and Bill Enyart, D-Belleville, as well as with congressional staffs from both sides of the Mississippi River.