By Brody Mullins and Drew FitzGerald

WASHINGTON -- A growing wave of big businesses are deciding to suspend or review their campaign donations in the wake of last week's riot at the Capitol by supporters of President Trump.

AT&T Inc., ConocoPhillips, Dow Inc., Facebook Inc. and United Parcel Service Inc. were among companies announcing Monday that they are halting or reviewing campaign donations from their political action committees to lawmakers and political candidates.

Those announcements follow JPMorgan Chase Inc. and Citigroup Inc., which said over the weekend they were halting their PAC donations, while others like Marriott International Inc. and Blue Cross Blue Shield Associations pledged to stop donations to the Republican lawmakers who objected to President-elect Joe Biden's victory in the Electoral College.

"Last week's attempts by some congressional members to subvert the presidential election results and disrupt the peaceful transition of power do not align" with company values, said American Express Inc. Chief Executive Stephen Squeri in a memo sent to employees Monday, announcing the company's decision to suspend PAC donations to more than 100 congressional Republicans who voted to challenge the election results.

Dallas-based AT&T, one of the biggest corporate lobbyists, said its federal PAC's board "decided to suspend contributions to members of Congress who voted to object to the certification of Electoral College votes last week." It wasn't immediately clear how long the suspension will last.

Hallmark Cards Inc. went a step further, asking two Republican senators who objected to the Electoral College votes, Josh Hawley of Missouri and Roger Marshall of Kansas, to refund PAC donations it made in prior elections.

"Hallmark believes the peaceful transition of power is part of the bedrock of our democratic system, and we abhor violence of any kind," the greeting-card company said, adding that its PAC is reviewing its contribution guidelines. Hallmark's move was earlier reported by Popular Information, a newsletter.

Decisions by companies to review or suspend their PAC donations is the most recent sign of corporate unease with moves by Republicans to call into question Mr. Biden's victory in the 2020 presidential election and could signal a broader desire on the part of business to distance itself from Washington -- at least temporarily.

The decisions may represent a widening fissure between the Republican Party and big business. Many Republican lawmakers adopted more populist stances on business issues such as trade and immigration policy in recent years, positions that have sometimes put them in conflict with the party's longtime allies in industry.

Chemical giant Dow said it would suspend PAC contributions "to any member of Congress who voted to object to the certification of the presidential election" through the end of each elected official's election cycle, which is up to six years for some senators. "Dow is committed to the principles of democracy and the peaceful transfer of power," the company said.

Corporate PACs are just one slice of the political fundraising efforts, and Washington is in the midst of a transition between administrations, a slow time for fundraising. Most PACs donate to candidates closer to elections. Also, many of the dinners and fundraising events that would typically happen in connection with a presidential inauguration have been put off because of the Covid-19 pandemic.

Corporate PACs are funded by volunteer donations from management-level employees and doled out to candidates by executives, usually in consultation with their lobbyists. PAC donations are an important source of money for incumbent lawmakers in both political parties, particularly Republicans in recent years.

In the 2020 election, Republican candidates and committees received a total of $205 million in campaign donations from corporate PACs, according to campaign-finance data compiled by the nonpartisan Center for Responsive Politics. Democratic candidates and causes received $155 million from corporate PACs.

Money from corporate PACs helped Republicans make up a deficit in campaign donations from other sources in the last election. The Democratic Party and its candidates received nearly 60% of the $3.6 billion donated by corporate executives in the 2020 election, according to the data.

Last week's votes by some Republicans to challenge the Electoral College process has prompted many companies to rethink donations from their PACs. Some companies, such as Goldman Sachs Group Inc., said it is temporarily halting donations, and JP Morgan said it is pausing donations for six months.

Other companies said they are reviewing their procedures for political donations, but will continue to give money through their PACs.

Marriott and Mastercard Inc. said they would stop giving to the Republicans whose votes they deemed to undermine the electoral process. More than 100 Republicans in the House voted to challenge the election results in certain states last week. Those Republicans included two of the party's top leaders, including House Minority Leader Kevin McCarthy of California. A handful of Senate Republicans voted to challenge election results.

Oil-giant ConocoPhillips said it is halting PAC donations, as well as corporate donations to other campaign entities, such as a political fund that supports Mr. McCarthy.

In the 2020 election, ConocoPhillips donated $500,000 to the Congressional Leadership Fund, which supports the election of all House Republicans.

"In light of the Congress's recent vote on the certification of the electoral results, ConocoPhillips has suspended all political contributions for at least six months," it said in a statement.

--Emily Glazer and Theo Francis contributed to this article.

Write to Brody Mullins at brody.mullins@wsj.com and Drew FitzGerald at andrew.fitzgerald@wsj.com

(END) Dow Jones Newswires

01-11-21 1659ET